Put the Motley in with her. He's plenty big enough to do the job. It's rare for a female to attack a male, but it does happen. Just make sure your female is well fed. Then wait 24 to 48 hours after feeding to put the male in. Don't give your female a huge meal. Just give her half what you normally would. Then, when you put the male in, watch them for a while just to make sure.
BTW if you male doesn't show interest within 30 minutes you should take him back out. My males normally take about 3 minutes to show interest if the female is ready. 
I know that most people say to give them a day or 2, but it really doesn't take that long to know if you're male will start breeding/courting. It's pretty much an "instant" reaction if it's going to happen. 