They do that sometimes, mostly with desastrous results for the female teams. The problem is that they can't really compete physically, in terms of pace and physical strength with their male counterparts. That's why the matchups are often with male youth-teams, where their phyisical charactaristics are relatively balanced.
To give you an idea, recent matches have shown that the German women soccer NT, one of the best in the world, is about on the same level aas around ~4th German division male teams.
Of course, female football lacks the infrastructure and support the male one has as well. Far fewer percentage of women try playing football, and therefore a far lower percentage of talents is probably discovered. Also, coaching and youth infrastructure is miles behind the one for men, and young female football players can't hardly ever count on making a living from the sport, so they'll not concentrate as much on training etc.