You know what is a great android game for girls... Any good android game. And that's because girls are people. They have a diverse set of interests and are not one single thing.
well done you! instead of meeting the OP half-way by trying to understand their requirements, you chose to shame them on the easiest of technicalities. Rest well tonight, good warrior, you've earned your propers.
+1. My youngest sister plays some weird fake Minecraft clone that's free on mobile. I have no idea what the game is about, but she loves it and gets to socialize with her friends over there
Unfortunately, if you're looking for a free download, the game you're describing doesn't exist.
The closest I can think of is Postknight 2. There's unobtrusive (optional) ads, and the full game is playable—start to finish—without spending any money.
It's very cute, and you can get pets... but it'll take some dedicated playtime to unlock them for free.
Oooooh I have some ideas! Some of these are paid/premium (but NOT micro transactions) and some have mild ads. But I share the distaste for data-mining, money grubbing, brain-melting-ad-ridden games, so I'm certain they are on the least intrusive end of the spectrum.
I really love biology (I'm a biologist...) so these are both pet games and usually breeding/evolution games!
Niche breed and evolve -- so neat and pretty educational about evolution/genetics. There's a slightly more complicated/difficult pc game if she decides she likes the nichelings/universe.
Pocket Frogs -- Simple, low stress collecting game. it would take years to collect all the frogs, and there's a relatively active community of people who trade sets of frogs to other people to help them complete collections. Would be fun to play with her friends at school!
Reigns Her Majesty -- a game about running a kingdom as a queen. When you die, you become your heir and retain some progress from your last lives. It doesn't fit the exact criteria you mentioned, but I think she might like it anyway!