How fun!! I would choose the Poly (such a great vibe/theme that all 4 of my girls adore!)!

You can have breakfast at Ohana, soak up the sun in the super fun pool, then eat a dole whip while watching fireworks on the beach.

If you ever want to explore/eat somewhere else, you can jump on the monorail and check out the other resorts nearby. I think it would be a perfect resort-only stay with your daughter.
Actually, this May I’m going to Disney with 2 of my older kiddos. We will only be going to the parks half of the time. We’re going to be much more relaxed, and really want to enjoy the resorts this trip. So, I told them we’d go for a week & do a split-stay so they could each choose a resort. My son initially chose AKV, but since we have 2 other trips planned for there within 8 months, he decided to switch over to CCV. My daughter, on the other hand, told me not to even ask bc I should already know
… she LOVES the Poly
All that said, there are so many wonderful options! Beach Club has the infamous Stormalong Bay, plus it’s so close to both the Boardwalk & Skyliner… Riviera is also on the Skyliner, has really fun details & scavenger hunt throughout the property (I know this isn’t unique to RIV, but my 11yo daughter really enjoyed this one, and it got her looking at all the paintings & details more), good food options, a nice pool & beautiful walking paths around the lake. Copper Creek is more secluded, has wonderful food and pool options, lovely walking paths, plus the boat to the Contemporary. Unless your fam really loves Disney Springs & wants to be there everyday, I wouldn’t choose SSR… but that’s just me. I also wouldn’t want to stay at VGF or BLT because they are walkable to the MK… and you’re not going to be going in. I think that would be tough with my 11yo- but the Poly feels just removed enough. IDK. Again, that’s just me.

Best of luck!!