Cat or dog is the most suitable or fish.

Search for small size cat/dog breeds.

Small fish like guppy and tetra. Goldfish is small and beautiful but it is not for newbie.

Make sure that you learned all the basic before hand as fish is not as easy as you think at first.

The fish tank require regular maintenance and a reasonable sized tank even for small fish.

For eg. you need to change half of the water of the tank every 2 week. Full water change every half year. Good water filter system and etc.

Only go for it if you are sure you can take over if your daughter losing interest.

Read this guide/FAQ
https://www.reddit.com/r/Aquariums/wiki/index/

Other small pets to consider are sugar glider and hedgehog. Do search and read the pros and cons first.