Ruling on a woman marrying someone who attends Mawlid celebrations and practices some innovations


My sister-in-law will be getting married soon. She is worried about the type of boy she can get married to. To be specific, she has asked me whether it is valid to get married to a person who is a strong supporter of the Mawlid or Milad-un-Nabi practice? I do understand that this practice itself is an innovation in Islam. However, the difficulty is whether one can get married to such people who practice Mawlid. In New XXX, the people involved in this practice, do this as an act of worship. People would be invited to attend this ceremony where various hadith are read, songs are sung and dua is made. People actually stand and sing! I hope this is the practice the fatwaa on your site refers to. The question is whether one can marry those who do this practice? The more difficult question and the one I am afraid to ask is whether these people are Muslims? Sheikh, you do not have to answer the second one if it is not wise to?