Fiona is so much better than she was, her swelling is almost gone but not all the way yet. Her tummy is dirty and sticky. She still eats, plays, drinks water etc but I need to clean her up a little. She keeps her paws and everything else in good shape but with her face swelled like it was I think she is having trouble keeping her tummy clean. I have a dry shampoo for gliders but I wanted to ask if there are any tips about what I should and shouldn't do.

Glad she's feeling better
I've never used the dry shampoo not sure if it will work on something sticky
You don't want to get her wet but damp is OK
take a washcloth with warm water on a corner and just pet her till she's damp thin dry her repeat till she's clean might not get it all in one day
Make it something nice so she doesn't get stressed out
Even if she still wet a little keep her against you in her pouch
Till she was completely dry

is her belly brown? wet looking? sometimes bacteria from abscesses are spread to the body from licking and grooming is why I'm asking, she may need something solution or cream to treat that.

Personally I'd skip the dry stuff what ever that is.

if you can handle her give her a "bath"

To give a "bath" first trim her nails ( trust me ) and wear a tank top so she can't get traction on your arms.

Get the water to the right temp you want it about the same as your body temp, check it by running the water over your wrist. When it doesn't feel warmer or colder its right, just like testing a baby bottle.

Hold the glider slanted keeping the head up and away from the water You can let her hold onto your other hand with her back feet and hold onto the tap with her front feet that way she will hold her head up out of the water still use one hand to support her back. Allow the water to run straight onto the gliders belly, DO NOT FILL THE SINK, LET THE WATER DRAIN. Once the fur is wet through use original dawn dish soap ( just a little on your finger tip ) to suds her up and rinse throughly.

Drying, NO HAIR DRYERS I prefer cotton tea towels, the fabric is easier with their nails as there are no loops like normal hand towels have and the cotton tea towels absorb water faster and get them dryer quicker.

Dry as throughly as you can, wad her up carefully in the tea towel n just rub her once mostly dry put her in a bonding bag/bra/pouch/down your shirt what ever she prefers and keep her on you until she's totally dry.

There is NOTHING wrong with giving a medical "bath" if it's done properly and one is needed. I've had to give a few of mine baths just be confident, keep their face up, talk to them and dry them well. If the belly is brown n wet looking have the vet to a tape or skin test to see if the bacteria has spread