At a hearing, the judge asks if you understand "X" What if later you realized you DIDN'T & atty had led you wrong

Someone in a recent divorce, still very emotional, went into the final hearing with all intentions of getting what was rightfully her share of a lawsuit settlement. During the last minute negotiations, she was told she could still receive the payments but would have to deal with her late husband's ex-wife forever. Thinking that no amount of $ would be worth having to deal with his ex, surrendered her right to her share, thinking, "at least my share will go to his kids." A week later, she found out that NO ONE will get her share and the kids will still only get their same amount, essentially, saying "no" to a monthly income for life (she's going on 67). Her lawyer did not know the laws and had led her wrong, but the judge, of course, ruled by her agreement that she understood. Is there anything she can do to change this ruling? If so, what? Is there a Statute of Limitations? Would another lawyer be needed? She'd want it to be worth the cost - Financially and emotionally. thanks