[crestokay]

I am thinking of getting a new female gecko that is ready to breed. Would it be fine to put her in with my male right away or no??

[Spyral]

No, you should practice a quarantine period before introducing any cresteds. 30 days is absolute minimum, 60 days better and 90 days best. This is to make sure she's not carrying parasites and is acclimated to a new environment. It's best to use a separate room from other cresties and other reptiles.

You also want to make sure she's keeping her weight steady if you are intending to breed them. Depending on where she's from, she might be low on calcium due to improper diet and should be given a chance to replenish her calcium stores if she's a former breeder. 90 days is probably best for that.