What to do with this money?

my mate and her hubby divorced, they had a joint account but it was overdrawn by 500pounds. no one wanted to pay the 500 and clear it and close the account. my mates suggested they both pay 250 each and have done with this. the ex hubby disagreed, he said she should pay the whole 500. so no one paid up and this overdraft continued...then all of a sudden my mate tells me 3000pounds have appeared in the account. and its been there all week., they have been divorced 3 years now, and dont see or talk as the split was not amicable. what to do withthis money inthis joint account? she asked me? im not sure?