Our mum's partner is living with us, what should we do?

Good p.m to you Aunty Amara and all the AVLites.
I'm 22 years and the last in my family of 3 girls, Please i need your help because there's a serious  problem in my family. 
The problem is that I and my sisters were single handedly raised by my mum alone because our father left us with the excuse that we are all females and my mum took it upon herself to train us in school and now my elder sisters are graduates but the problem facing I and my sisters now is that my mum wants to remarry...geting married again is not our problem but the man that she wants to marry is now living with us in our house built by my mum and he has not done any proper marriage rites, to us, its a shameful thing because it has made tongues to start wagging both within and without that our mother is housing, feeding, and infact training a man that is not even helping us in anyway possible. 
Please what should we do?? I'm desperately in need of help because men are not even askin us 'how far' because of the situation and friends have all gone.i'm so sorry for the long write up please. Thanks.

Dear sender, 
I know that you so much care about your mum and about what people are saying about her decision to remarry and her choice of partner. 
But maybe I should remind you that none of those people talking today stood by her when her husband left her for reasons she wasn't responsible for. 
None of those talking today brought soup nor bought soap for shower. 
Every night, she slept alone in the cold weather. She endured the satisfaction she ought to get from her husband. She looked horrible so that she could raise you all in the university. 
She deprived herself of her happiness to build the house that people are now poke nosing to know who enters and who doesn't. 
She must have made efforts to reunite with her husband but they all failed. 
None of your friends offered to help nor did her neighbours cared to know her silent pains and tears. 
Today tongues are wagging because she decided to give love another chance in her life. 
And suddenly they knew his profile and chose not to talk to you. 
Dear if only you knew what your mum has experienced, probably your tone of mail would have been much different from what I read. 
Gather your siblings and find out more about her feeling about the relationship. 
If she is happy with the man, all you can do is offer her support and appreciate her for all she has done for you all. 
Encourage her to make proper investigation so as not to fall into the hands of gold diggers or irresponsible man. 
And offer her a lot of prayers that God would guide her footsteps. 
Pretty soon, all of you would be getting married and that would leave her with no one to talk to, communicate with or share her heart with. 
You cannot make decisions for her, but you can suggest or encourage her to not to make a mistake in her journey to find happiness once again. 
Every lady wishes for a happily ever after but a woman rejected by the man she loves only wish to be happy. 
Please it's not time to judge her but time to be a source of happiness to her.