Well, what about it is actually being hard about it.
it's just a fact that uring happens, and if she isnt changing you then about the only thing you can do is to keep yourself clean.
When you need to change, if you want to, do it in the bathroom, put in a bag so she doesnt see/smeel the diaper.
Perhaps wear pajamas over the top all the time if you dont, if seeing a diaper bithers her.
You need to ask her or least say what you know/think is bothering her.
I mean, in all reality, she bleeds every month and used a pad or tampon for that, this is life, and shouldnt be anything to be bothered by, it's like everyone uses the bathroom it not something that can be avoided.
My suggestions without specific info from you:
Change when you need to, use some scented powder too.
Wear pajamas over the top of the diaper, if not a diaper cover too.
Change in the bathroom, dispose of the diaper asap and/or put in a seperate bag right away.
Maybe keep things trimmed to keep smells as bay.
If being intimate, take a shower right before, and if there is any issues with any spillage then maybe get a bed pad, but that isnt usually an issue anyhow.
Besides that, i cant think of any general thing that you can do, but please post if you have specific things she is having issues with, i may be of more help once knowing that.