We are a family of 5 and have the same issues. I was SO tempted to get two connecting rooms at a value or mod, but connecting isn't guaranteed. The whole point of the two rooms, for us, was so that DH and I could have some privacy. We chose not to take the chance.
Alligator Bayou at POR can sleep 5, but since we planned to spend resort time I didn't relish being so cramped.
That left the Deluxes. WL's standard rooms, as noted above, only sleep 4. The Deluxe Suite will sleep 5 but is really expensive and not eligble for discounts since it's a suite.
BC and YC have a great location for EPCOT, but my kids are young and I can't count on spending that much time there. The pool area is huge, and keeping track of 3 young kids would have been a nightmare. There is no one place to sit that you can see most everything. The rooms are not overly large.
GF is lovely but I felt the rest of the family wouldn't appreciate it as much. Also, it's the most expensive. Lots of dining choices, nice pool, spa will be out of commission for a while but has exercise facilities open.
CR has a great location for MK, great rooms, good dining choices but lacks a bit in the ambiance column.
POLY has a fantastic location for MK and EPCOT, along with TTC. Lovely atmosphere, easy access it it's own restaurants and GF's, large rooms, fun pool for the kids and small enough that I'll be able to keep an eye on all three. The lack of a hot tub or exercise facilities do not affect us...wouldn't use either. This is what we chose. Location, dining opportunites, pool, large rooms and ambiance won it for us.
If she is not concerned with location, a 1 BR at OKW will have a bunch of room and is often offered at a substantial discount from Disney. Also, renting points from a
DVC owner may be something for her to consider if daily housekeeping isn't necessary.