It must be challenging for anyone to try to contain a family member's behaviour when he or she is in the manic phase as their energy level is high and their mood is elevated. Oftentimes the manic individual will have unusual ideas, e.g., that he or she is extremely wealthy (and would start to give away money or prized possessions) or that he or she has special powers or abilities (e,g, to save the world from destruction). How can a relative cope with that?
First, one can try to acknowledge the patient's emotional state. For example, by stating 'I can sense that you are getting excited and feel that you have special powers.' 'I can feel that you are upset that people around you try to prevent you from spending money.' Second, we can try to distract the individual by talking about other issues. Third, to persuade the individual to take medications and seek consult with a psychiatrist.
It is going to be hard to correct her beliefs as she will firmly hold on to them and refuse to budge. In fact, they can become aggressive and violent when they sense that their relatives are trying to prevent them from executing their plans , e.g., to save the world. It is also not appropriate to play along with the delusion as that may reinforce the abnormal belief.
An important measure is to gain her trust and to get her to give her credit card to you for safekeeping as individuals in the high state are likely to swipe their credit card many times and lose control of their spending. If the person drives, it is important to get him to stop driving when he is in the manic state as his judgement on the road may be affected and he can also become rather impulsive.