Retainer Fee has been paid

All -

I paid our retainer fee today. I have a question. Currently our
checking account is in a bit of shambles - however - our lawyer said
to leave it the way it is and go take our paychecks and deposit is a
new bank for a fresh start. My question is that my mom has a
signature card on our account. We put her on there so if she ever
had to buy anything for the kids or take them to the doctor she
could use our money.

If we just leave that acocunt like it is : will she be liable for
that money? It's just bank fee's not checks outstanding - I don't
want to leave her in limbo.