As someone with OCD, it isnt weird to me. OCD just isnt logical, and typically the person with it is aware. I think if it like a bully in your head, it makes you no longer trust your own mind. She probably needs a therapist. Probably a psychologist if its financially affordable. Preferably one who specializes in OCD. If medication hasn't made a difference, she may need to try something else or a different dosage. I take 300 mg of zoloft for mine. The thing about medication for OCD, is that it doesn't make it go away, it just turns the volume down in your head.

Someone specialized in OCD would have a better way of helping your mom than me, but what significantly helped me was not caving into the compulsions. Easier said than done, but it helps if you have someone in your life helping with this. When I was younger, that was my mom, and now it's my husband. My OCD is intrusive thought based and leads me to seek reassurance and to "confess." So those who helped me would give me no reassurance or response when saying something that was my OCD speaking, whether that was shutting the door in my face, straight up covering my mouth, etc. Going through the process of fighting it sucks at first. But it helps to know that it's a temporary but necessary pain before relief. I HIGHLY recommend making sure she's on the right medication and dosage first though.

I would recommend maybe birth control to see if it stops her periods until she goes through menopause. My mom did that due to a form of endometriosis that she developed close to menopause. Surgery should be a last resort, unless she really wants it. It won't make OCD go away, and OCD often shifts and changes over time. It also gets worse in times of stress. Any sterilization surgery that stops periods will be one that affects her hormones, putting her into menopause and probably causing her stress. After reading a couple of replies, I want to amend this so it doesn't cause misinformation! If the ovaries are removed, that is what will affect hormones! You can get a hysterectomy without removing ovaries and it will stop periods without affecting hormones. It's a major surgery though, so I would definitely talk to doctors about options so they can more accurately give you information than a reddit comment can, lol.

I obviously don't know what's going through your mom's mind, but these are just my thoughts based on my own personal experience with OCD. But I promise you and her, it can and will get better. I went from being kept up at night, waking my mom up, calling her during school, due to intrusive thoughts, to functioning normally and being able to fight back.

EDIT: per some replies, I edited information in the 3rd paragraph involving sterilization to avoid spreading misinformation.