Is it Permissible for a Sunni Female to marry a Jafari Shia Male

Is it Permissible for a Sunni Female to marry a Jafari Shia MaleCategory: RelationshipsIs it Permissible for a Sunni Female to marry a Jafari Shia Male
Hasina asked 6 years ago

Assalamu Alaikum Brother
 
I am writing to you today to get some advice on a dilemma we are facing in our family.  My niece (sisters daughter), she is 25 years old. She has recently told us that she has chosen her marriage partner and wishes to complete the process as soon as possible. 
The problem is, we are all Sunni Muslims and the male she wants to marry is Jafari Shia. 
From childhood to now, we have been refrained by family to have no any association with Shia’s, it’s a massive taboo. With their beliefs as Shia’s and ours as Sunni’s, its meant to be a definite no go. 
The question i need to ask you is, is it permissible for this marriage to take place?   Secondly, if it is not permitted, we as family members supporting her to complete the process, will this be sin upon us?
My sister is  divorced from my nieces father,  so she has no other support apart from us, her fathers side of the family have not been around, which means any marriage processes, we will need to complete, but we have already advised her that  we need to find out first if we are allowed to support her as non of us are willing to compromise our deen. 
If it is permissible and there is no sin, then we as a family can complete this process asap to prevent  further sin, if it isn’t permissible then we will need to tell her that we are unable to offer her any support. 
She will marry this person, the question here is,  whether we can do it as a family ceremony or she will have to do it by herself with the male and his family. 
In sha Allah I hope to hear from you soon brother. 
Jazakh Allah Khair