I remember her talking about the man she was with and they had a "love exchange" ceremony, with just some friends there, party type thing, but it was not anything legal on paper. So technically this is her first marriage.
It could be that the father of her children gave up his rights, and this man David adopted them, so technically she could get away with saying "the father of my children", because if he adopted them, then he is.
But the guy that was in the pool in her backyard when she had her last baby is not the one she married, so if one got picky, yes, this is her first legal marriage, but her new husband is not bio Dad, but Dad nonetheless.
She is a flower headband hippie sort of girl. She seems over the moon happy, so good for her!