Part of the problem is that you get no indication of how the maid is feeling from her side of the relationship ... although we have successfully married a Sim to the maid in the past. In her case we knew she has 'Commitment Issues' but we got there in the end. It was very hard work, but we wanted her to do a lot of work around the house and especially in the
huge produce garden.
One option might be to "Invite Over" and "Try for Baby" using a sarcophagus [needs no preamble, so quicker than trying to do it nicely
]. I have no idea how the resulting pregnancy sorts out any residential issues though.
Oooooh, Pam ... you CHEAT