First, congratulations.
Now, breeding a female and seeing locks does not guarantee eggs. Does she even have follicles yet?
Four months is exceptionally short. Ive had everything from 4.5 months to 12, and thats just the girls that go that year. You really cant start counting on anything until ovulation. An ovy is the only time you can count on getting something (whether it be eggs or slugs).
If I were you I would leave her at your friends house. You want a gravid females life to be as low stress as possible. Moving her back to your house would seem tempting, but you might end up with more slugs from stress or her not going at all.