I [27F] need to figure out how to convince my mom [54F] her online military boyfriend [?M] is a catfish.

First time poster on mobile, sorry for any formatting issues.
Let me preface this with stating that my parents have always had a turbulent relationship. My dad is an alcoholic and my mom is... difficult. They argue a LOT over stupid things and my dad just does nothing to show my mom love and affection.
Which leads me to the fact that my mom has been having an online affair with a ‘military’ man for roughly a year now. She didn’t tell me this stuff- I found out through watching her live makeup videos to her beauty community. She tells these women everything and they validate it all.
Here is what I know from piecing everything together:
-He claims to be in the French military for America. He’s on a ‘secret’ mission where he is put to sea? Or that is at least what it seems. He claims to have broken his phone and cannot get a new one since he’s out to sea.
-Because of the previous point, he uses his friends phone. It’s been almost a whole year and hasn’t replaced it.
-He claims he cannot send videos/record them himself due to his mission- yet recently his ‘friend’ sent my mom a video where he is in it for a second. This seems odd that the men he is with can record but he cannot.
-He has two daughters in a boarding school in Florida. He asked my mom towards the first half of the relationship if she could open a bank account so that he could wire her 5k to pay for his daughters expenses. Why would he be in a situation where his daughters might need a stranger to help them?
-He’s said he is getting out of the military to move to the US MULTIPLE TIMES. He’s come up with en excuse every time including shooting himself in the leg once. This caused him to stay on his mission. He sent her a very close up picture of a gunshot wound on a leg.
-He doesn’t have his own Facebook. He uses his ‘brothers’. The last public post was in 2017.
-She got a job a month ago. She sent him a phone recently to an... agent? It apparently missed the flight and the agent says she has to pay $150.
My parents relationship has ended for other reasons. My dad told her to leave two months ago (doesn’t know about this guy), but tries to still take care of her monetarily. She recently moved back in and is basically using his money even though she is divorcing him to be with this catfish.
She won’t hear anything against this guy and is isolating herself from her sisters so they can’t argue against it. How do I approach this without her losing her crap? She watches my daughter for me as I cannot afford childcare so I have to toe the line in order to not ruin our relationship or my childcare.
I love my mom, but I’m not sure if I can keep our relationship if I speak out against this guy.
TLDR: my mom is being catfished by a fake military man and now they’re taking her money.


Source.