I'd be careful about grabbing her hands. I get my hands forcefully grabbed all the time. Especially when I ask to be handed something. Other then that just include her. I know she is 4 but I think she will do her best to tell you what's not working for her or at least try.

A few smaller things that people don't really think about, maybe some for older kids.

Don't fret about her injuring herself. My wife says she become very cautious about a lot of things simply because as she got older more people starting fretting about her running in to things, so it kind of comes back to just treat as any other kid. She'll just do her thing for the most part.

She can't get her own drinks, food, or find the toilet. Make plenty of offers especially for the toilet until she learns her way. I still get this when we visit people. If I'm not right beside her my wife will sit there for a long time wanting a drink or a pee because she's not comfortable asking people.

Plenty of streaming services have "audio description". Disney plus has a lot.

It's pretty much common courtesy but everyone does it. Avoid talking about her while she's there. Beyond the obvious accidental overhearing, she probably has better hearing, and in most cases blind kids develop their speech and understanding a lot faster than other kids so she understand more than you think. A lot of my wife's "issues" come from other people's comments and just general feeling of being embarrassed about a lot of things. The longer you put that off by being positive and confident in her ability to take care of herself and do things the better.

This ones a bit tougher (or at least it is for me as I'm not talkative at all) but if you can get used to describing the things you're talking about or seeing that'll probably be nice. Like if you see a dog doing something funny and everyone laughs, try to remember to stop and describe it to her. Allows her to enjoy it and makes her included.

We don't have a blind kid, and I'm not blind myself, this is just stuff I've thought about after hearing my wife's experiences as a kid.

Treat her like a normal kid... except don't suddenly grab her to guide her.

Hey! It depends on her level of sight. It's pretty hard to tell with someone that young but maybe you can ask the parents? In general, treat them as a normal kid! Identifying yourself is good, as well as any pets or visitors in the home. If she's in your house, walk her to the important areas such as play room and bathroom so she can get her bearings. Most toys for a child that age can be played with without sight. Toys tend to be pretty tactile and less complex. Simple boards games (such as candy land or whatever kids play) can be fun too. She can draw her cards and pick her playing piece and you just help her move her player across the board. Coloring and crafts can be fun too. Things like playdo or clay is fun and tactile. But even coloring is fun too! Just let them draw and see what they may come up with. Building blocks or legos can work too. I don't know what you have at your house so I'm trying to give you a bit of a variety. The only thing I would stay away from is throwing balls/objects around and anything sharp should be kept away (like any kid). Otherwise, just let them have fun!

My sons best friend is blind. For starters I identify myself and I say his name every single time I ask a question or speak to him. They enjoy music a lot now but as kids they played a tactile game , basically filling a box with stuff and 'blindfolded' they each would ID things and choose items to ' keep on their side ' it sprang from a weird game we bought that involved a farm and a spinner for tactile play.
When serving food make sure you put drinks and snacks in the appropriate position and keep your home clear if tripping hazards etc. Just some thoughts. Over the years his being blind has had little impact on activities ( for example we went to a Broadway show when they were tweens and they both loved it ) just seeing she is a person who deserves to be heard too and that she will learn different strategies for some things. His mom was learning too but was a valuable resource for things like how to keep out bathroom accessible and for sleep overs where/ Joe th place his items ... we learned as we wen.
She will some extra supervision around safety when your out and about. Outdoors

Ask her if she needs help instead of just doing it for her. Blind kids need to learn that they can be independent but there isnt shame in needing help. Some adults do everything for their blins kids and they learn to depend on adults actively when they are capable of learning independence. While others have an isolated feeling because they feel like no one will help them when they need it. If you notice them struggling, say "would you like some help?" "If you want, I could do that for you." "Here! Let me show you a way you can do this"

These phrases give the child a sense of independence and capability without making them feel alone