How to Make Her Cum

Excuse me, would someone please help me out here? I've been wanting to see my now fiance cum for quite some time now, especially since I've never seen a girls flooding before, but whenever we have intercourse now, even though it's sometimes even above 10/10 I can't hold the pace and strength level for more than like ten minutes- I believe -without making myself reach my own climax. Of course our sex lasts over twenty minutes, but nothing is either good enough or lasts long enough to make her cum. When I finger her at this specific spot however, she tells me not to do it too hard because apparently it makes her feel like she's going to pee herself if I press it in too much while rubbing it, but it's her favorite spot as far as I can tell. I understand that intercourse alone may not be enough to get a girl to climax, but what I want to know is, "What are the other things that must be done?" After intercourse she doesn't want to do anything else because she's 'too exhausted' but I still haven't seen her ejaculate yet, and I know that she can since when she masterbates over the phone with me it only takes her anywhere from two- or three since she said she was doing it for a minute already before I new it -to maybe a little over ten minutes to cum. I've even seen cum around her vaginal entry that she apparently forgot to clean up from the night before when she masterbated- I didn't know -so I know that she can cum. I figured out that for me, the longer period of time that I keep myself from doing anything that would make me cum, the sooner I cum while we do have intercourse, so I figured that maybe it's the same for girls, but I don't know, the thing is though, I doubt she'd even hold out for very long even if I asked her to. So would someone please be kind enouh to tell me what I can do? She absolutly refuses to masterbate in front of me as far as I can tell. The only time that sh didactually masterbate from me asking her to- who knows how many times -she stopped like three seconds after. I don't want anyoneto say that I'm forcing though, I just want to see HER do it. She's seen me do it plenty of times. It's not very fair.