I have an 11 year old and a 9 year old, both girls, DRASTICALLY different. My kids have always had tv in their rooms, though we do have controls on their tvs and do monitor what they watch, mostly both my kids still watch Disney, Nick, ABCFamily (mostly the older stuff), and my 9 year old is very into Food Network shows lately. They do both have cell phones, which are locked to only allow calls to/from their contact lists, which started out with just family members (me, dh, my parents, sister, etc). They got them for emergencies after the school put them on the wrong buses (not the same wrong bus either) last year so they could reach us if needed. I have since added a couple of my 11 year old's friends #'s in her contact list, and she talks to them on the phone a couple evenings a week, she hates texting. My 9 year old only has the family in the phone but she loves texting and texts me and dh frequently.
In a lot of ways my 11 year old is still into more of the "younger" stuff than my 9 year old, she still likes Hannah and adores Demi Lovato & Selena Gomez, likes HSM, etc. My youngest has decided this year that she is not into Hannah anymore, however she carries a baby doll around with her most of the time. She is very into Taylor Swift. Neither has an IPOD brand, both have MP3 (9yr old has a mix stick and 11 yr old has a Sansa shaker) because they like having their own music. I didn't like to listen to all the same music as my parents when I was a kid either, so I don't blame them, my husband listens to country or rock, I listen to a little of most things, depends on my mood. Both my kids listen to classical music at night to go to sleep, have been to ballets, opera, etc.
I guess, OP, what I am saying is that part of the differences are personality, and part are age differences between 10 and 13, I'm sure. Is your neice overindulged? Possibly in some ways. Do you limit your dd? Maybe a little, but you know your child and it is your right to parent your way. We haven't started with makeup yet at our house, though most of the girls here seem to start with a little blush, eye shadow and lip gloss in 4th or 5th grade. The girls thus far only want lip gloss and that only rarely. I don't wear a lot of makeup either, but can remember being in 9th grade and not allowed to wear makeup, and we would sneak it to school, I guess that's not a battle I think I would fight. Now as far as being allowed not to participate with the family, I would not allow that one either, but I guess they know their child too...