My daughter is 20 only worked a month and half can I claim her and her 2 babies and how would she claim her taxes

IF you supported your daughter and her children in 2022 then you can claim all three of them as dependents on your tax return.  If she can be claimed as your dependent--and it sounds like she can be---then she cannot claim dependents herself.  Dependents cannot "have" dependents.

She can file his own return for a refund of some of her withheld wages (she won’t get back anything for Social Security or Medicare), but MUST indicate on it that she can be claimed as a dependent on someone else’s return.    She should not enter anything about the children on her return if you are claiming them.

WHO CAN I CLAIM AS A DEPENDENT?

You can claim a child, relative, friend, or fiancé (etc.) as a dependent on your 2022 taxes as long as they meet the following requirements:

Qualifying child

• They're related to you.
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They're under the age of 19 (or 24 for full-time students).
• No age limit for permanently and totally disabled children.
• They lived with you for more than half the year (exceptions apply).
• They didn't provide more than half of their own support for the year.

Qualifying relative

• They don't have to be related to you (despite the name).
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They lived with you the entire year (exceptions apply).
• They made less than $4,400 in 2022.
• You provided more than half of their financial support.

When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them. There may be other tax benefits you can get when you claim a dependent.

Related Information:

• What does "financially support another person" mean?
• What is a "qualifying person" for Head of Household?

To claim a grandchild as your dependent

When you enter the child’s name in Personal Info, you will be asked “What’s your relationship to  [child’s name]?”  

           Choose “another person”

            a drop down menu will appear that lets you choose grandchild

Yes you can claim both her and her children if they meet this criteria:

• They are not claimed as dependent by anyone else.
• They are US citizens.
• They live with you? Your daughter and grandchildren must live at your residence all year.
• She made less than $4,400 in 2022? 
• You financially support them? You must provide more than half of your relative’s total support each year.