Billy's Mother: Both a sympathetic single mom & a cold calculating bitch

I'm not sure about the "Sympathetic" part. She was a desperate and very lonely woman who was desperate enough to take escapees in with little regard to her and her sons safety. Would that be a reality? Very unlikely....If she was ugly and dim witted maybe, but she seemed pretty together and wife like. It's too hard to believe she'd just jump in with Tony like that without knowing more when she had a kid to worry about too. If they made her some lush stuck out there that would have been easier to believe