1. She is your mother and this is good scope to repay her debts to some extent.
2.Forget what she is entitled to or not. The asking for money from court must be a warning to you which you could have avoided.
3.ANyway beofre the matter gets nasty though the proceedings in court, settle with her and start giving her money.
4.A mother is reasonable enough if she expects that her son would look after her on death of her husband and such fulfilment of expectation through court of law must her last ditch attempt.
It is wake up call which you must not loose to pick.