And, criminy, almost every woman on the planet between 15 and 45 has a period once a month. Lucky for you or you wouldn't EXIST. So, I guess it is a bit of a sore spot with me that it is UNMENTIONABLE, and that women are subtly still treated as unclean and disgusting because they, gasp, shed the lining of the uterus monthly. Even worse is that this is just another societal issue that cramps a woman's sex life. (Pun, accidental, but recognized )
Anyway, back to you and your SL, lol. It sounds like you are NOT part of the problem, which is most excellent. However, I have to wonder just a bit how true what she says is versus how much it is what she feels she must say. For instance, just like maybe W used to think she had to be a good girl during sex, she may feel strongly that she has to be grossed out by sexual activity during her period. The first doesn't have to be true, nor does the second. Indeed, like I said, a good O could really make her feel better during her period. (Yes, women talk about these things sometimes and agree...)
Still, if she finds such things icky, not much you can do about it. Still, no reason your R can't continue to benefit from physical intimacy. She can always, ahem, lend you a hand or ... and may be happy to do so if you ask her for a little help because she is driving you crazy with lust... You seem to have the passion w/o neediness thing down pretty well, so it might be something that actually is good for you both. The intimacy is still loving and good for you, W, and your R even if it is a bit one-sided. Things can always be a bit one-sided the other direction some other time, lol.
Enough, like I said, this is just something that bothers me in general because it is part of the bad messages and mindsets going around that really undermine the healthy sexuality of women. But, in your particular case, it seems as though you have addressed it positively and openly, which is great.