Well done on the steaming!
I would try letting a fever run it's course too. Especially if Anna doesn't seem extremely bothered by it. I think in the long run it might help. Like you said though, watch the temp and don't let it get too high too long.
Breastmilk is sometimes considered by some docs as "dairy" like formula... Breastmilk is NOT dairy, and is as good or better than water for sick babies. For the comfort, for the antibodies, and for the nutrition value. That she's spitting up a bit is normal, if she's got some post nasal drip her cough might be triggering her gag reflex a bit.
Tasha is there a place you can get live probiotic capsules? Like a good healthfood store near you? They are little capsules of powder like stuff that looks like a regular health supplement or vitamin capsule. Inside are live probiotic cultures. I've sprinkled baby's diaper area with the insides of these capsules.
Probiotics are the good bacteria of our bodies... in our intestines and in female reproductive tracts
Keeps everything neutralized and healthy. Sometimes we get "too clean" down there and loose our good bacteria. It takes a little bit for that good stuff to build back up so taking a good probiotic and sprinkling a little in her diaper may help get things started.
You can also eat good whole organic yogurt to help build up the probiotics.
If it's thrush, you'll want to make sure you are staying clear too... just as with sexual partners you can exchange a thrush infection between you and your breastfeeding baby pretty easily.
There is also a product here in the states that we call gentian violet. It is available over the counter but it isn't something that is available at most pharmacies. This is a potent anti-fungal and will really attack thrush infections in breastfeeding pairs. The bad thing if you choose this method is that you will have purple nipples and Anna will have a purple mouth.
https://www.bflrc.com/newman/breastfeeding/gentviol.htm
Oh, and as far as how I learned all this stuff... I love human biology. It is fascinating to me. So it's a bit like a hobby for me
Good thing I have this hobby as I love having babies!
Hope Anna is feeling better soon!