Congrats! When did you get her? That time line suggests she wasn't gravid when you got her but most likely one of your males got the job done since you had her in Dec. If she laid on the 19th that would mean she ovulated around the 2nd of Febuary. Good luck and hope you see some pastels or spiders.
Side note, its hard to resist putting males on new girls when you get them but you should allow for quarantine time. Not sure if you did or not but just thought I'd mention it for anyone who's reading.
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