Well, hopefully the GM put this in there for a roleplaying/game mystery purpose and not just "haha paladin, joke's on you! Your ma's evil, suck on that one, loser!"
So, what's ma's backstory? If she's a 5 hd evil character can she be redeemed? Is it really the Paladin's mother or a doppleganger or something worse?
If she's an unrepentant evil character, who ultimately can't be redeemed (and who sadly, will likely commit small evils over the course of her life, as its her nature- even if she isn't looting and killing) and cannot be converted to even neutrality, then the Paladin may have to break ties with her. Although, that is the least interesting of the possible scenarios.
