Certain flowers can be eaten, but make sure they are safe.
I am currently growing pansies and marigolds for mine. Just be sure that there are no animals using your moms garden as a toilet and that she doesn't apply dangerous pesticides/fertilizers/gopher bait in the garden. A google search or search on Guinea Lynx should turn up a list of safe flowers for them to eat.
The "read me" sticky in diet and nutrition forum has a list of poisonous plants. Unfortunately, it's not a complete list of flowers, but it may rule some out right away.