Honestly, virgins really are not going to be a lot tighter...if she's got an intact hymen then it's going to hurt her a bit even if you put a little tiny dick in there after an hour of glorious foreplay...though she's gonna want it in there, and her tolerance for pain will be high as a consequence of the arousal and desire she will feel if you're any good at all. If she's nervous then she might clam up down there...start with one finger (with short, filed fingernails on well groomed, and washed fingers!) while going down on her...then add the next finger, and maybe even a third finger. Be gentle, don't scratch her, and make sure that her pussy is aroused, and welcoming. This isn't about virgins, it's about pussy...a woman with 20 years experience will still tighten up if she's nervous or not ready yet...
The hymen is not terribly thick, and if you get her well prepped with lots of foreplay, make her cum first, have some lube, and use it on her as well as yourself, take some time, and have the slow and gentle variety of sex then it's going to be OK. It's gonna hurt her some, and that pain will linger perhaps for a few days (my first gf wasn't a fan of sitting for 3 days.). Don't worry about rocking her world with your cock the first time - she might not come from intercourse (ever) she might not act like a porn star (ever) but the experience should be about MUCH more than the mechanical act of fucking....make love to her. She is sharing something very special with you - act like it, respect it, love it, and be good to her.
Oh and I'm not gonna touch your stated size with a 10.5 inch pole, but I will say that even a 7 incher can't just pound away on a women without making it hurt, so you're going to need to make sure to ease into it for the rest of your life, even after you've been doing her for 15 years, and even if you aren't quite 10.5".
Once again...make it about loving her, her entire body, her mind...and not about your dang cock. A virgin might not be able to tell the difference, but later on, experienced women will want more than just a ram in the lungs.