I started my daughter at 4 or 5yo.  I have lotsa minis from way back, which is the key to staying alive as we all know.  She is now 8yo, and loves to paint minis.  We have also moved on to building some terrain.

1. Reaper minis or others that are easy to wash, need no or mini primer works best.  I wouldnt worry about the details, since they will work it out…and by the looks, your daughter is doing great

2. Youtubes – short youtube videos are great to get them aware of technique, which is very helpful for myself as well.

3. Keep the minis in line with what your daughter is interested in.  My daughter is really wanting to paint some mythic battle minis, but I think I will wait for her to get a bit more skilled first.  I do let her paint Shadow of Brimstone characters, esp as she loves to play the game.

4. Lastly – be as open and willing to allow her to make choices that she likes. It may not be what you want, but you have to live with it.  My guess is you are fine, but not all my friends are that way.  So not all my minis look like I want, they are worth more for the knowledge that i have hooked my daugther into the gaming world.

My biggest concern is the day that she is more skilled than me….at which time she will have to buy all her own supplies and minis….or maybe paint my armies.

Oh I almost forgot, getting a mini holder helps too – as well as a good brush or two.  I also alway try to get her to do 3 minis at a time, so she lets them dry and she can add what paint is left of a color to another mini before moving on.

Best of luck,