How Old is Monica?

The actress is in her mid 30s. Cheadle is early 50s. Yet the way the characters were shown it seemed like they were roughly the same age. Was she supposed to be older?

And Roscoe is what, 16 in Season 5? Which means if Monica were in her mid-30s, as is the age of the actress, she would have had him when she was 20 or so, ie even before finishing college. Doesn't seem like a woman as driven and as insane as Monica would have had a kid that early, she would have run, not walked, to the nearest abortion center and got rid of the "problem".