I’d say female as no pores. Females can have a bulge, esp around toilet time…plus if it was a male, the bulge would have a line/dip in the middle splitting the balls providing it is an adult.
What weight / age is the Crestie?
Going by my Cresties, if infertile they have no routine as to how often they lay most of mine only laid 2 times a year if never bred.
I wouldn’t breed a Crestie just because it laid eggs, weight is more important. I’ve had a few girls lay eggs but aren’t at weight. I wouldn’t breed till min 40g but ideally 45g
I did a little bit of info on ways to tell the sex if you would like a read it