Need Help From The Experts Please!

Might as well say up front, i don't have much expieriance with geckos. I have learned a lot from this site, but i still have some unanswered questions i was hoping someone out there might be able to help me out with. I have a male Standing Day Gecko. I have had him for a little over a year now. I keep him in a 55 galon aquarium. It took me a while but i finally found a female. The only problem is that she is only a couple months old. About 6" in length. I was told by the man that sold me the female that i couldn't put them together untill she gets bigger. So i got a 10 gallon aquarium to keep her in until she is big enough. I am just wondering if the 10 gallon tank will be big enough for her and when she is ready to go in with him how should i go about putting her in there? Someone told me to keep their tanks side by side where they can see each other for a couple days before i put her in. Just not really sure how to do it, i really don't want anything to happen to her, took to long to find her. Your time and suggestions is greatly appreciated.