Welcome to the STD forum.
It is very unlikely you still have the HPV infection that caused your warts; HPV infections, especially the wart-causing types, usually are gone in a matter of months and cannot then be transmitted to sex partners. However, having had a few sex partners since then, most likely you have had other HPV infections that you don't know about, and you could conceivably could still be carrying it. No test is available, so there is no way to know. Of course this is entirely normal; HPV is unavoidable in sexually active people. Also, some virgins catch genital HPV infections; exactly how is not known. These reasons are why all women need regular pap smears. Even if you are correct that she has never had sex with anyone else and never will, she could still have an abnormal pap smear or other HPV problem someday.
I'm not saying you have HPV. In general, it sounds like you have led a conservative sex life by modern standards, and there is absolutely no reason for you to feel guilty because of the limited sexual activity you have had with your current partner. Even if you had had unprotected intercourse, there would be no reason for guilt about it. (If everyone with past warts or other HPV problem avoided sex out of guilt, most people could never have sex!) In any case, dry humping doesn't transmit HPV.
And for many of the same reasons, your partner should consider getting immunized with Gardasil, one of the two available HPV vaccines. It will prevent her from getting warts (in the unlikely chance you still carry that particular virus), and also will protect her from the 2 HPV types that cause most cases of cervical cancer. She should discuss it with her primary care doctor. (Be aware that it takes at least the first 2 vaccine doses -- i.e. a couple of months -- for the vaccine to provide partial protection, and full protection requires the third dose at 6 months.)
As for informing your partner about your distant past warts, there is no medical reason to do so. However, in the interest of open, healthy relationships, many couples discuss their past sexual and STD experiences. But many do not, and this is a relationship issue, not a medical one. You could get some opinions about this (probably with both points of view) on the MedHelp HPV community forum.
Here are a couple of older threads that discuss these things in more detail.
http://www.medhelp.org/posts/STDs/hpv-QA/show/742564
http://www.medhelp.org/posts/STDs/Handsfield-6-month-disclosure-guidelines/show/552283
Bottom line: This is a non-issue, or should be. Don't let it bother you.
Regards-- HHH, MD