how should we handle this case? my brother died 5 mths ago n he left beyind 2 houses, 1 for wife n 1 home deed over to wife+ sister.

my brother added my sister's name on the deed years back and he wanted that way, because wife already has 3 houses on her name. a lawsuit from a tenant which had lived in 1 of the apartment of the house in ???, lawsuit has both my sister's + wife's name. wife wants my sister to sign deed over to her, so wife could own all 4 houses + wife wants to take care the lawsuit alone. my sister own a house her own home but reluctant to sign over the deed because their is a pending lawsuit + sister will lose her share of that house. the house insurance company assigned a lawyer to represent wife n the lawyer wants my sister to join in + to remove my sister's name from deed. the lawyer told my sister join in or the insurance company will cover her in the lawsuit. 1:should my sister sign over the deed n get it over with or should sister stay on the deed and fight the lawsuit + her share of the estate? 2:how does sister get her share of the estate form this entangled web?. 3:marriage is ?/not sure