I am sorry your kitty is having trouble :(.
I am glad to hear that you are going to the vet, anything involving the eye can be pretty painful. Try to have your kitty seen Monday morning if at all possible, because waiting too long can result in some scary complications, depending on what exactly is going on. There are a large number of things that could be going on with your kitty, so giving advice on how to make her feel better until you can see a vet is going to be difficult. That being said, there are some things you can do that will not adversely affect her.
First, make sure she has access to areas of your home that are low light. Bright light, and even changes in light brightness causes pupils to dilate and constrict, and this is painful for an injured eye. Rule of thumb: squinty and uncomfortable needs low light.
Second, consider picking up an e-collar from the pet store. Even if you don't see her rubbing her eyes, she likely is. These types of issues are uncomfortable, and sometimes the eyes are very itchy. If she is allowed to rub her eyes (either with her feet or by rubbing her face on something), she can actually damage her corneas. An e-collar is standard for cats with any kind of eye problem. Your vet may have the soft e-collars, which are much better tolerated and more comfortable, but since they are soft they don't work for all cats. Reference the link below to see what they look like.
Finally, if she has discharge from one or both eyes, you can clean around the eyes several times a day. Take a soft wash cloth, soak it in warm (not hot!) water, and gently cleanse around the eyes. Be sure to wash your hands after cleaning her eyes, just in case there is a bacterial component at work.
There are several things you should NOT do until you have seen your vet and know what is causing the symptoms you are seeing. Do NOT put any eye drops into her eyes. Some conditions are worsened by certain types of drops. Do NOT let your kitty go outside, she can further injure her eyes and if she has impaired vision she could be more prone to injury. Finally, don't delay getting veterinary attention for your kitty. Some eye issues can lead to permanent scarring, blindness and loss of the eye (worst case scenario.
Please let me know if I can be of further assistance. Best of luck with your kitty :)