She should talk to her ob/gyn about getting Imvexxy. Its an estrogen insert into the vagina. My wife needed this a few years ago and it allowed us to have sex again. Its likely, I'd say certain, she's beginning or is in menopause. Low libido and dry vagina, sounds like my wife before HRT for menopause. Now my wife is a river again. She is so wet from HRT she quit the Imvexxy because she was dumping grool all day long and irritating her pussy from the extra wetness!!
Also your wife should take this supplement called Slippery Box. Its slippery elm bark and it helps mucuosa linings lubricate, aka, the pussy. Its helping my wife, its been good for women for a while now.
She should also take supplements for her pH balance in her vagina. She should take Metagenics Ultraflora Women's. Its bacteria like in yogurt but it targets the vaginal pH and helps balance it. This helps with wetness and especially discomfort. For the last I don't know, maybe 13-15 years now, I can't cum in my wife because it gives her a bladder infection. Every damn time we've tried, same result, she needs antibiotics. She'll go 6 months no UTI and one cum from me inside her, off to the doctor. But now, she's been on this Ultraflora stuff once a day, I've cum in her twice and its like I never did at all. I just pumped a massive load into her a few nights ago and by now she'd be burning. No sensation or anything remotely like a UTI came on. Its like a miracle!!! I mean she loves when I shoot on her and I love it too, but every now and then for the emotional intimacy it brings, cumming in her and us cumming together is just mmmmmmmm so good. Like Monday night lol!!!!
These are my suggestions instead of lube. If she's got her libido down, she won't lubricate and her pussy is not engorged with blood so that means painful sex. Period. If she's even the slightest bit horny she'll have a better time. And foreplay isn't enough. She's got to have the mood for it, and the blood will start flowing.