You can currently get Jennie, Diane, Daisy, Eve, Grace, Odette and Consuela pregnant, with child, knocked up, in a family way. Once they're in that condition, you can only continue to fuck Diane - pregnant sex with the others would be a nice touch.
Anyway, what other females are next to become eligible? Debbie? Mrs. Johnson? Aqua? Ms. Bissette? Ms. DeWitt? Ms. Okita? Ms. Ross? Roxxy? Becca? Missy? Crystal? Roz? Make them all eligible and you'll have to add another pregnancy floor to the hospital - you can already overload the hospital now with six pregnancies for four rooms.
Then, when Daisy keeps delivering calf after calf after calf (she's got a quick recycle time), what happens when the male calves and female calves start hitting puberty (or whatever it would be)? Does Diane or MC have to neuter (deball) the male calves so that they become steers instead of bulls? Will MC have to service the young, pubescent cowlettes when they see how he services their mother? The game just keeps getting more and more interesting, opening up a variety of options.