Height and body size have no correlation to how much you can take. I've been with a girl who was 4'10", and I basically was exactly at the limit she can take. I was with a girl who was 5'7", and guess what, we couldn't really have a good sex life because it didn't fit. The key to this is being calm and trusting the other person. Over time you can make anything fit, you just have to be calm about it. Just like Mr. Black said preparation with dildos can help a lot, but someone taking their time and keeping you calm also helps.