(NSFW). A virgin?

I am that guy who believes in sex as a sign of ultimate trust and love.
I had dated many girls before this one whom i so badly would love to believe i ‘deflowered’. To be honest, I avoided virgins all along because I didnt want to be held ‘responsible’, sex outside marriage is strongly not voted for in my culture.
We have been dating for almost nine months now and only started to have have real sex last month. According to her, I am her first and wants me to be her last too. She is not my first though.

About 3 months ago I fingered her and was surprised that both my two fingers( fore and middle fingers) could fit in her vagina without her complaining of any pain. When i asked she was furious at me for doubting her. And i let the case rest and kept quiet about it.

It was last month when we decided we have our first real sex as she said she was ready. And she didn’t bleed, however, I found penetration not that easy and she did say it hurt a lot.

Now my question is: (a)- Can two fingers (mid and forefinger) fit in when one is a virgin, and (b)- Can a non-virgin trick one into believing she is for example by tensing her vaginal muscles to make penetration a bit difficult?

I am in a dilemma. I do really love this girl and (now that I deflowered her,??)would like to marry her. But I don’t trust her (on that subject only), because she grew up a naughty girl and dated twice more than I did and mostly bad guys, and lied to me once to protect her so-called boyfriend. Telling her my worries now will just cause a heartbreak. Help.