My mom recently reentered Assisted Living, but Medicaid is still pending.

She lived there on Medicaid several yrs ago then left to live in a retirement home that didn't accept Medicaid.  Her Social Security check and her ex husband's (my step-dad) pension check went towards her rent.
 Before she left AL the first time,  my husband and I sold her car for $800 cash and gave the cash to her to spend for what she would need in the independent retirement home she moved to...for example food, necessities etc. and she has no receipts.

 Now that she has several strokes and needs more care she is back in the same AL and reapplying for Medicaid, they want to know how she spent $800.

I need suggestions on how to handle this please