We have to use a good portion of mom's money for her care expenses. Do we have to claim that as income?

Are you saving the rest for her? If she doesn't already have a plan you might consider pre-paying for her funeral/memorial service etc. That is, if she can still understand that and agrees.

And congratulations on coming from a supportive family. Mom must have done something right in raising you all!

A good portion for her care, ok. What about the rest? If you are using that for your own expenses, there will be a problem. Keep her money completely separate from yours, in a separate account in her name only.

It's not your income. It's your mother's. So no, unless somebody better qualified than me (i.e. any American! :)) tells you different.

But what I would urge you to do is make absolutely sure that your mother's money is kept hermetically sealed off from yours. Her own bank account, and careful records of her expenses and her share of the household budget - a pro rata proportion of the utilities, local taxes, etc. It's fine to spend her money on her, but for peace of mind keep track of every cent.