If the mom decides to not give in to the blackmail, there could be a big family drama. The person blackmailing might carry out their threat and cause embarrassment or problems for the mom. For example, if it's about a secret that could affect the mom's reputation in the family or community, it could lead to arguments and a tense family atmosphere. And if she does give in, it might encourage the blackmailer to do it again in the future.
The mom might feel very hurt and betrayed. She could start to distance herself from the person blackmailing her. Also, in some cases, if the blackmail is illegal or unethical in nature, there could be legal consequences for the blackmailer, even if it's just a family situation. For instance, if the blackmail involves something like false accusations or threats that are against the law, it could lead to trouble for the one doing the blackmailing.