Just my 612.60 Zimbabwe Dollars worth,
Based on my admitedly layman's research, the vagina (that thing we poke with our prods) is the inverse of the penis (that thing we guys discovered after the novelty of sucking our thumbs in the uterus wore off). There are size differences between one person and another. These differences may or may not be linked to the overall size and/or body structure of the person involved. Many times they aren't.
The main thing to remember is that the vagina, like the penis, is "elastic". Just as a man's penis has different sizes, so to does a woman's vagina. However, unlike the erect penis, a woman's "erect" vagina has the ability to mold itself to the optimum size and remain there for the duration of intercourse (within its normal inborn genetic parameters, of course) granted that it is given enough time to adjust to the size it's receiving, vaginal "erection" being much slower than penile erection.
Think about it for a second. The vaginal canal is able to pass a full term baby. This is an extreme example, as childbirth usually entails a great deal of pain. As Carol Burnett once said, "Imagine your lower lip being pulled up over your head". However, despite this, many women deliver vaginally without any extreme change in the size of their vaginal canal. Certainly there is occaisional tearing at the vaginal entrance that requires suturing, but the main part remains intact and eventually recedes to its normal size.
Whenever you hear a guy say, "My girlfriend's pussy is so stretched out on accout of (her ex being hung like a elephant) OR (her having sixteen kids)" you can safely assume that he's undersized.
AAARRGH!!
I tend to get wordy when I'm tired, sorry.
I guess what I'm getting at is that most women of any height can physically accomodate various sizes of cocks and still feel fulfilled within their pre-dispositioned range (which has little bearing on their height).
The only physical research I can confirm is that my "very petite" wife (4' 10") had trouble handling me at first (about 7.5", ruler laid across the top, if that's the way to measure?). I used to "hit bottom" on a regular basis at the beginning of our relationship, but rarely do anymore (she seems to enjoy it even more
.
I can only conclude that she has elongated to accomodate me. The grip about the girth is still the same.