For custody issues, absent extreme circumstances, custody cases don't end until at least the child turns 18. Getting an unfavorable settlement here is a problem, but likely isn't unrecoverable. Typically a judge won't modify a custody arrangement without a change of circumstance; but they do have considerable discretion.

For the financial issues; this is what lawsuits are for. If her law firm does not make her whole on their own, she should hire a legal malpractice attorney who will probably be able to convince them.