You say that your wife suffers from lichen sclerosus, a condition that creates skin tissue that is thinner than usual (and is a higher risk for postmenopausal women). Warming oils and lubricants, unfortunately, create discomfort rather than arousal for her. I'm not aware of an option in that category that would work for her, since the ingredients that make them effective--usually something minty or peppery--will almost certainly cause an adverse reaction.
Plain lubricants won't cause that reaction; those we include in our product collection should be well-tolerated by lichen sclerosus patients.
There are a couple of other options you and your wife could explore for arousal. The use of testosterone has been beneficial for 50 to 60 percent of the women in my practice who've tried it. Testosterone is by prescription and off-label for women, which means a discussion with her health care provider is required.
Other prescription options include localized estrogen, Osphena, or Intrarosa (a recently available FDA-approved choice). Any of these would increase blood supply by "estrogenizing" the genitals, which can improve arousal and orgasm as well.
Congratulations on undertaking this exploration together! Good communication and mutual support are so important to shared intimacy.