Something like this could be good as a introduction.

https://store.steampowered.com/app/3214720/Mouse_practice_for_kids/

Its specifically made for very young children to learn basic mouse controls/coordination.

https://store.steampowered.com/app/478010/ABC_Coloring_Town/

Microsoft added Solitaire and Minesweeper in part to get people used to using the mouse.

I would only use the XP version at the latest.
https://archive.org/details/solitare

♥♥♥♥ 10 and 11's "solitaire collection" malware.

There's plenty of classic point and click games for kids, like Putt Putt and The Playroom and Fatty Bear and the Edmark Early Learning House games and Thinkin Things and The Secret Island of Dr. Quandary, etc. to the Adventure Game genre like Maniac Mansion, King's Quest, Monkey Island, The Dig, Loom, etc. for slightly older kids.

https://classicreload.com/the-playroom.html
https://store.steampowered.com/sub/42719/
https://store.steampowered.com/app/317030/Fatty_Bears_Birthday_Surprise/
https://archive.org/details/BAILEY_WIN
https://classicreload.com/the-secret-island-of-dr-quandary.html
https://archive.org/details/msdos_Thinkin_Things_Collection_1_1994
https://store.steampowered.com/app/529890/Maniac_Mansion/
https://www.gog.com/en/game/kings_quest_4_5_6
https://www.gog.com/en/game/the_secret_of_monkey_island_special_edition
https://www.gog.com/en/game/the_dig
https://www.gog.com/en/game/loom

The Living Books games were cool.
https://archive.org/details/GRANDMALB97
https://archive.org/details/NewKidOnTheBlock

were my favorites

https://www.old-games.com/download/10200/entombed is a good one. And more approachable than the Myst series.

They make mice specifically for toddlers as well.

This one might avoid your little one becoming bored quickly with multiple games on offer:

https://store.steampowered.com/app/3355240/Teach_Kids_Games/

https://archive.org/details/sound-it-out-land

I've been trying to remember the name of this one for years. While AI is going to turn out to have been a catastrophic bubble, it is occasionally useful for advanced websearches.

My grandmother got the CD ROM for my younger brother, though I enjoyed it, despite being a much higher reading level than it's intended for. Very catchy redbook songs. And Doom elevator sound.

My sister is a year and a half old and she likes this game, of course with my help but suitable for little kids. Your granddaughter is only 2, she’s still too little but games like this are great because they teach colors and drawing
https://store.steampowered.com/app/1507410/Coloring_Book_for_Kids/