I will tell you the same thing I would tell a provider being threatened to be sued by a client ... save the emails she sent, save the phone messages to a digital device if possible or leave them on your machine, ask others who've seen or heard her threats and behaviour to document it NOW while fresh in their mind her exact words and claims and so forth, if they saw his soaked pants, unopened wipes and diapers and so forth to record that statement and so forth with the date to keep it 'accurate' in their mind and document and save ALL your correspondence from your end of the deal to back up why you feel 'just' in your termination of the contract.

BTW ... what was your 'contract' with her around termination and grounds? Does it address a 'probation' period or anything where either party can terminate during that time 'without notice' if things are not a match? In absence of that how much notice did it require on your part to terminate? The neglect claim on your part aside .... just wanting to get a feeling for WHY she is thinking she is entitled to an additional MONTHS pay from you if she got paid for the month of March in advance and you pulled him on March 16th ... she already got two weeks PAID notice which seems more than fair if indeed her service was not 'up to standards'???

I realize and so do the courts that there are ALWAYS two sides to every conflict in life which both parties feel passionate about them being 'right' and often somewhere in the middle is the truth often shrouded in miscommunication / personal perception of situations and so forth which is what they will try to find ... if she is to take you to court it is likely cause she honesty believes she did not do anything WRONG so either that he had been 'dry' up until moments before you arrived and she had just not had chance to change him yet cause some kids CAN hold it for a long time and than 'flood' out and that is why she is feeling entitled to proper 'notice' in her mind cause your reaction from her perception was unjust ... so perhaps she changed him as she says using other clients stuff?

Although IMO I will admit using other clients supplies on a child is so NOT COOL practice unless it was an EMERGENCY like the kid ran out and it was borrow or sit in a poop diaper ... cause some kids are allergic to certain wipes or diapers that is WHY we ask parents supply them and parents should have every reasonable assumption that this is what WILL occur?

I wish you the best of luck in your resolution of this - conflict is never fun and the stress of being sued is NEVER fun .... ideally maybe mediation between someone at small claims would be a better way to go for everyone!