So everyone here thinks that if you can leave your children at someone's house, or have the person come to your house to babysit, then it's a free for all? You must then also trust that person to TAKE your kids away somewhere?
Do you trust every one of your kids' friends' parents to take them away for a weekend, or to drive them just anywhere?
And the "but it's her sister" argument doesn't cut it. As someone else posted (and I can't find it now), just because you share DNA, it does NOT necessarily change the comfort level of the parents to allow the other person to travel away from home with their kids.
Honestly, some people here act like the parents might as well be signing over complete and total legal custody of their children, rather than just be asking someone to "babysit".
Congratulations to all the people here who have FABULOUS siblings, parents and grandparents who make them feel SO comfortable that they don't think twice about letting them take their kids anywhere they so choose. Good for you! But that doesn't make people who DON'T "crazy". Unbelievable.
I just told my DH about this thread, and we had a bunch of laughs (we can laugh now) about his parents watching our kids. Nice, sweet couple they are. But they do have older grandchildren, and I was always a little leery about how much freedom they gave those kids. Like when my MIL told me what a great cruise they had with all of them (parents there too, also EXTREMELY easy about their kids' freedom)...after I expressed that "*I* wouldn't have felt comfortable letting them run around a cruise ship like that", my MIL said "Oh MaryAnn, you can't get in trouble on a cruise ship." ??? And on two cruises after that, the boys (4 of them, from about 18 - 14) got drunk and puked all over one of their staterooms, and as they got older (at least a couple still underage) jumped off one of the upper decks into the water (the parents and grandparenst saw "people" fly past the restaurant window, until security came to fetch them about the kids); and then there's the story of one of them, maybe 14 at the time, spending half the night in the room of some girl he met...all told as "cute" stories. All of these kids survived, and the oldest is now 28, and I enjoy their company, but would I let any of their parents, grandparents (my ILs) take my kids anywhere,
at any age? NOPE.
We did let our kids stay at my ILs a few times over the years. I figured how could one overnight here and there
at their house hurt? There was always something that made me a little uncomfortable, like letting 2 yr old DD run around in the yard eating from a papercup of WHOLE grapes (MIL had never heard a child could choke on whole grapes! Around that time another child in RI choked (and died) on one, in the grandparents' care;
MY MOTHER knew they were a choking hazard.). The last time...the VERY last time...my kids spent a night there was about 6 years ago, when they were DD(12), DD(10), and DS(7). Over the next day or so, bits and pieces about their weekend came out. For ex, in the morning, my FIL dropped the kids off at his DD's house. However, the DD wasn't home...she was taking her DD to college (FIL knew this). The ones who were home were two of the above mentioned boys...one 16 and one 21. The 16 yr old took them on a bike path with borrowed bikes and rollerblades...and no helmets...and my kids said (when asked) that no, they didn't always have their cousin in sight. Back at the boys' house, the kids hung out
in the boys' room. DD(10) said what a mess it was. I said that the oldest one will learn some organization when he goes into the Army. DD(10) says "The Army??? And here all he does all day is lay around in his underwear." I nearly hit the roof. All the other little things that bugged me over the years about the ILs, we kept our mouths shut and let it slide (except to tell them they needed to cut up grapes for a 2 yr old). This time, no way. DH called his father and said that when we leave our children in THEIR care, we expect them to remain in THEIR care. That was THE last time our kids stayed with them. I'm sure my ILs thought (and still think) they'd have more FUN with their cousins, and they ARE their cousins, so what's the big deal? And geez, they didn't get HURT, right?

But my kids would have been thrilled enough staying at grandma and grandpa's, or going to the movies with them or out for ice cream...whatever...with THEM.
As far as independence...my kids are extremely independent. They've been doing sleepovers at friends' house since K, and they always separated easily...loved just having a good time at someone's house (but I would hardly think that I should then feel equally as comfortable letting these same parents take my kids away for a weekend). DDs both went to away camps...DS didn't want to, and that was fine. By the end of April, all 3 will have been to Europe (youngest at 14), without us, and without a single doubt about being so far away. (Yes, I'll worry, more about terrorism than anything else.) When 2nd DD was 14, I sent her to Florida to stay with my niece for 3 weeks to help her with her 4 kids. I trust my niece. I would not trust my sister for those 3 weeks to properly supervise a 14 yr old. By her side every minute? No. But I wouldn't put it past my sister to let her "date" a boy in the neighborhood.

I have encouraged (just short of insisting) all my kids live away at college; oldest is a freshmen and flourishing on her own. DS(14) is in a soccer program and will be traveling, without parents, to programs around the region and quite possible the country, as well as to England in April. No DNA involved with the group...trust? Yes.
The "envying their children having fun without them" just makes me

. I'd LOVE to see my DS play soccer in England...I'd love to GO to England. But one of the reasons I chose NOT to is that I think, honestly, he'd have a better time without me there! He's growing up (14), most parents AREN'T going, and he doesn't want me there anymore than he'd want me tagging along at summer camp. And I think that's great!