it can be very difficult to plan a
DVC resort trip for those who are used to standard sort of resort cancellation policies.
Repeated for emphasis.
OP, if you talk your mother into this and then your brother bails, or someone gets ill, or pregnant, or can't get vacation time, or the kids have a soccer tournament - most rentals are FINAL.
We've taken friends and family.
The first time we were supposed to take my mother in law and father in law. A few months before the trip, my father in law decided he couldn't get time off work (didn't want to go in reality). We were able to sub my husbands aunt, and it worked out great.
The second trip was supposed to be with my family. My parents, my sister/brother in law/nephew, and my sister and her boyfriend. This one is a saga.
First my sister gets pregnant and is due about the time we are going to travel. Fortunately, we've planned far in advance, we take a solo trip with the family and move the trip out a year. Pregnancy is a great reason to cancel, no hard feelings. Then we discover that my other sister is being abused by her boyfriend and ends up in rehab for alcohol. That doesn't change the trip, but we will come back to that later. The baby is born, the trip is on with baby in a stroller, and that sister gets cancer. Trip is postponed again. (Again, can't exactly blame her for having to go to chemo instead of Disney). This time we sub in a few friends (who turn out to be the most miserable traveling companions ever - that in itself is a story - but they were available and we had a room). My sister recovers (yeah!) and we finally take the family trip - without my other sister who has successfully sobered up (yeah!), but is single and in a funk and decides she can't handle that much family time. So we end up spreading out a little more than planned. Not a huge deal. (And understandable, her sobriety was a long journey, it was pretty fresh when we went, and she was having a tough time realizing that maybe she'd never have a family - seeing her sisters families was tough). She is healthy, happy, and married now - no kids, but that was a choice).
A few years later we plan a trip intending to bring my brother in law - who has terminal cancer - and my mother in law again, and my brother in laws girlfriend. He passes away a few months before the trip. No one wants to go and me and two kids occupy a Grand Villa (my husband joins us but not for the whole trip). Again, can't blame anyone.