The other poster is wrong, don't use zinc oxide. There's nothing "wrong" with it, but it will get on the diaper and cause water to "repel", and basically ruin the absorbency. If you do have to use zinc oxide, or other OTC rash cream, expect to strip the diapers after the rash is cleared, to restore them to their original absorbency.
You can use extra virgin coconut oil and a disposible liner inside the diaper. California Baby and CJ's BUTTer are also both cloth diaper friendly. If you don't want to use disposable liners, you can use a preemie or newborn prefold as a doubler, but again, you'll need to strip them every couple of washes to get the oil/lotion residue off.
The best thing to do is to determine the cause of the diaper rash. Usually it's due to prolonged wetness against the baby's skin, so factor in changing her a bit more frequency for the duration of rash healing. Also, make sure it's not a yeast infection. If it's a yeast infection you will need to sanitize your cloth diapers in between uses to prevent spreading the yeast back to her (check with the manufaturer on sanitizing your specific brand)
Look at the brand of wipes you are using. It might be worth it to switch to cloth wipes and homemade solution. Wipes are INCREDIBLY easy to make. You can just cut a flannel receiving blanket into pieces and zig-zag stitch the ends, or even just buy a few terry cloth baby washcloths. Make a solution with some water, a teaspoon or so of baby shampoo, a teaspoon of coconut oil, and a few drops of lavender essential oil. Store it in a spray bottle and just spray each wipe before using.
Check the detergent you're using. She could be experiencing irritation from detergent residue on the diapers. Switch to a cloth diaper detergent like rock n green, or use tide free and clear. And only use a few tablespoons per wash load and maybe add a 2nd rinse cycle to make sure all the detergent is washed clear.
It could be a food allergy. Are you introducing solids? Is she experiencing any other allergy symptoms, like loose stools or bloating?
You can add a bit of baking soda or epsom salt to the water when you bathe her, that will help with the uncomfortable irritation. Then make sure she's completely dry before putting another diaper back on. You may even consider a few hours of "commando" time each day where she doesn't have a diaper, so the area can get some air.