I think that's pretty accurate. When Peach is up high, it's hard to avoid Pika's thunder. Her recover options are limited because against a lot of characters, if she has her float she will just recover really high. That option is removed against Pika, mainly because of that blasted slower air dodge.
I think this is a pretty even matchup. Peach can do ground floated nairs and bairs to combat QAC's. Even occasional use of Peach bomber discourages use of QAC. In shirt, Pikachu can do some nasty combos to Peach and has less problems killing her than he does the rest of the cast, but I believe QAC's is highly, highly reduced to a limited role in the matchup when Peach is used to it and knows how to combat it. Peach's priority can give Pikachu fits, and his priority and spacing/speed combination can give her fits. He can't really chain grab her - the best way for Peach to get out of a low % CG is to just simply hold up to float, and the second the float comes out (you can dodge the grab by floating and you won't go back down into it since you float your first possible free frame) and then you nair to prevent him from reading this and punishing it. Autocancel the nair if he reads that one, and land with a jab.
Does Pikachu CG peach at all - as in, is it frame guaranteed or no? I can never tell because I usually take a lot of damage avoiding grabs at low percents (i fall into stuff since i'm avoiding the grab so much) so I've avoided having Pika's do it to me, but I can't tell if it's frame guaranteed or not.
One effective thing Peach can do to edgeguard Pika is a trick I learned from Vijdo back in Melee against Melee pika. Same idea applies. Just float in front of the ledge and nair when he tries to QA or forward b into it. Pika's recovery is good enough to just simply choose to go on the stage instead, but if you surprise him you can get in a lot of good edgeguarding hits. Also, it takes away a usual reliable recover on the ledge because nobody else in the game can just hog the ledge like that and attack you while protecting it. Even MK has to drop and regrab. Peach can jsut float there in front of, sort of "guarding it" and when Pika QA's into you you can reflexively input nair as Peach. Nair lasts long enough where even if he quick attack's another direction and uses the second into the ledge, you will still hit him.
I also agree that Thunder jolts are good against turnips. Really limit them. .Turnips still have some uses, but they are hard to use well, and give her the same approaching advantage they do with, say turnips against a metaknight.
Even matchup to me 50-50. Both chars got a lot of decent tricks against the other. I'd say that Peach has better range and damage racking capabilities whereas pika kills a little earlier and camps/plays a better switch up defensive/run and attack game.
Last point - Never take a shower when a pokemon is around. He will Peek-a-ch-you.