So the first thing is that you say she "claims" to have low libido, which indicates a distrust of your wife. I don't know why you feel that way, but perhaps that's a good topic to bring up with her and maybe a marriage counselor.
Menopause is a bear. I'm in it, so I know.
Libido is affected by a serious drop in hormone production, fatigue, changes in sleep, body changes, vaginal changes, etc. Even if she's still getting wet, the vaginal tissues thin, and can become easily irritated.
Is she on any hormone replacement? Every woman's needs are different, and hormone replacement isn't without risk. She should talk to her doctor about this. The general guideline for women over 50 is an oral estrogen and progesterone, and a vaginal estrogen, but again, every woman is different.
Masturbation is so much easier than sex. Do you masturbate? Do you ever masturbate just for the release? Just to maybe get some sleep or improve your mood? Maybe that's what she's doing. It doesn't have to be about you. Women masturbate for reasons other than their partners, just like men masturbating for reasons other than their partners. Masturbation isn't always about partners not being satisfying.
If she's having night sweats, hot flashes, sleep disturbances, insomnia, maybe she's just too tired for sex. Maybe she senses that you aren't really buying into this low libido thing, and is just as upset as you are.
At some point, she may not get as wet as she's getting. That won't mean, necessarily, that she isn't as aroused as she is now by you. Vaginal tissues thin and vaginal dryness occurs. Please don't take this personally. Her body response isn't always about you. Talk about it, and get some good lube.
My suggestion - and do with it what you will - is to talk to her. Gently. Tell her that you don't really understand what's happening, and you're sorry if you've come across in any way that makes her feel uncomfortable, but you want to know what she's feeling. If you told me, as my husband, that you think I'm "claiming" to have low libido, I'd have a lot of feelings about that.
You're her husband. Be her safe space for this. Talk to her doctor about what to expect, if she's okay with it. Read up on menopause. (https://www.gennev.com/education/menopause-help-for-husbands and https://www.verywellhealth.com/supporting-your-partner-during-menopause-2322673 and https://menopause.org/ )
She isn't suddenly interested in someone else, if that's what you're thinking, or suddenly NOT interested in you. She doesn't suddenly find you unattractive, unappealing, or not love you.
Don't be one of those men who distrusts their wives because of your insecurity. I don't know if that's what is happening here, but I have to say it just in case. She's going through a whole lot more than you right now, I promise.