So the sentence ' She has two children with him' should be in the form of passé composé in French.
If the children and mother is still alive, it would be better to write either present tense or present perfect.
The verb is bear and the past participle is born. She has born two children.
She has two children with him.
OR She bore him two children.
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She bore him two children. I think your sentence represents even the simple past form. Please tell me.
Elle lui a fait deux enfants.
So the sentence ' She has two children with him' should be in the form of passé composé in French.
"Elle lui a fait deux enfants" literrally means "she has made two children with him", thus the passé composé. Talking about both parents ("Ils ont deux enfants") would be more above the belt and less derogatory, because you would talk about the children themselves, not about how they were "made".
"Elle/Il fait un enfant" means that he/she is having sex.
"Il lui a fait un enfant" means that they had sex and she got pregnant. Yes, the end result is that they have children, but said that way, this is derogatory.
She/He has a child - keep it literal: Elle / Il a un enfant