Hi M.,
I'm sorry your baby is experiencing this! Sounds like an allergic response to something (or some THINGS) in her environment or food. I experienced this with my infant daughter (who is now almost 4) and I didn't know then what I do now about the effects of food sensitivities and environmental triggers with little ones. The Aquaphor is an attempt to give her some comfort but isn't going to take away the actual problem.
It can be tough to pinpoint what it could be at this age so what it means is doing an elimination diet at this point (I am assuming you are breastfeeding). Dr Sears has a good one for really eliminating most any known "trouble" food though I've heard it can be a bit tough to stick on it for a long time. The health of our little ones is a big motivator though!! Common allergen culprits include milk and all dairy products, corn and all corn products, soy, wheat, gluten, eggs. There are others but these are biggies for many people.
If you are supplementing with formula at all that could be the problem. We were advised to supplement when my daughter was tiny (I now question the wisdom of that decision) and her skin only cleared up well after I eliminated that and she was exclusively breastfed again by around 3 months old. The reality is that formula has things in it that are NOT good for human babies, it's kind of like junk food for babies. Yeah, I know the formula companies don't want us to know that, but it's true. :(
You might want to switch to an even-less-allergenic laundry detergent too - Dreft still has fragrances and additives. Shaklee brand is good (I don't sell it but have used it), and 7th Generation is supposed to be, I heard (I think you can get it at Whole Foods). Careful with the cleaning products you use in the house too, and about any pesticides that might have been applied in your yard or neighborhood - some kids are very sensitive to such things and will have marked reactions.
For baby skin care have you tried Aveeno baby products? Or California Baby? And have you seen a pediatric dermatologist - it would be well worth it and they might prescribe something helpful like Elidel cream (it's non steroidal) to help soothe and calm her skin.
Best of luck in helping your baby girl - I know how tough it is to deal with this kind of mysterious rash.
Blessings,
S.