if she needs steam games to buy instead of powering through her eternal backlog, I'm just going to shoot wildly based on a vague idea of what she enjoys because I still don't understand it to this day, but I can at least guarantee for the games' enjoyment:
"My Time At Sandrock", sequel to "My Time At Portia", is a 3D farming/life-sim that actually has a direction and gameplay that isn't just straight up aping stardew valley. It's my go-to recommendation for chuubas that crave the eternal farm-adventure-social loop and have put one million hours into SDV. Story mode's over 100 hours long, multiplayer mode has its own progression and quests, and the company releases free major content updates each quarter ever since it left early-access:
To help fund the quarterly content updates, they have quite a few cosmetics, outfits, furniture DLC, so only get those if you enjoy the game and want to support its development. That being said, the one DLC I can readily recommend as a purchase is the Monster Whisperer, which adds Monster Taming/Catching to the game, thus adding another notch to the cycle that Palworld started. It's not on sale because it released recently, but it very much aligns with Pippa's interests:
And here's easy access to the previous game, which also boasts an incredible amount of content, and has story/character/lore tie-ins since these games exist in an overarching world (as will their inevitable third game in the series). Sandrock is a mechanically better game than Portia, which should go without saying, but I need to account for whatever brainworms may prevent chuubas from looking into it - it is a good game, you will probably enjoy it:
And from the same studio is a School Building Sim, isometric, which started as an internal experiment but was so beloved that they put resources into it to make it a full game. It also follows the same "free content updates funded by cosmetic DLC" as the My Time series, and it seems to be working out for them: