Will the supplication of the neighbor and her mother against the questioner and her children be answered, after she informed on her son's misdeed that led to his admission to the reformatory? And is it permissible for the questioner to supplicate against them, or is it better to bear their harm with patience?

Concealing a Muslim's faults depends on a sharia-compliant interest. If you have done what is permissible according to sharia (even if it is contrary to what is preferable), then your neighbors have no right to curse you. Your cursing them is permissible if it is in response to their harm and you have not exceeded the limit. However, it is preferable to pray for their guidance. The son who harms his parents must be advised to repent.