To provide any useful advice we need a plan with dimensions. Graph paper with each 1/4” square representing 6” is usually easiest. Mark locations of all fixed items like windows, plumbing, etc.

Totally agree with the above comment. Also be aware that some of those walls that you are looking at moving, maybe loadbearing that would necessitate something else to support the ceiling/ roof or the second floor.

I’m working on the drawing of the room. It’s a one story house, so I wouldn’t assume these are load bearing walls, but great point.

Consistent flooring through the whole space would make a big difference I think - something to keep in mind -

The wall with the frig and range is the most important for configuring with an island. I'd like to see a floorplan with everything including what's behind that wall from one outside wall to the other.

In this case, there are supports inside the walls that support the trusses that support the ROOF!!!!

Someone will have to take a look in the attic to see how the trusses are beling supported because that will factor into what can be removed.

There are still loads with a one-story house. Where the kitchen ends there is a change in the ceiling/roofline, which means there are probably substantial roof timbers that need supporting along that line. Get advice from an engineer before getting too far along.

Start with an architect to see what can be removed or opened with posts remaining. Get rid of the angles as much as possible - they actually waste a lot of space. Give us a floor plan with dimensions and what the results are from the architect.

Once we have that - you will be amazed at the awesome ideas these folks will give you!!

This space has great potential!

and help my sister build her dream kitchen

Help your sister by getting her involved in this conversation -- it's her dream ...

Maybe your sister should buy her dream house first. Overdoing one room and putting all the money into it, while the rest remains old and shabby, is about the worst idea ever. Either plan to redo all to be equally redone, or redo the kitchen at a much more downscale level, that matches the house lived in.

In the mean time ( while you are looking for an architect ) , go ahead and draw a floor plan with all dimensions ( including the full living room area ) . It is hard to tell from the pictures the true space you are working with.

This can become a really great space for your sister - we just need to sort out the areas involved.

"We’re just trying to think of how we should demo this. I was thinking of tearing down the weird walls and opening the kitchen up to the living room. I just can’t decide which wall to go with because she doesn’t want to lose cabinet space, but having a larger island with a sink and dishwasher built into it is on her list of wishes for this kitchen."

This is cart-before-horse. You can't remove a baseboard right now because you don't know where you're going. Demo starts on paper, way before the pry bars come out.

And demo isn't just crazy fun hammer swinging like on TV either. All those dangling wires have to be labeled. It's more complicated than it looks.

Yeah, and when you take down all the walls, you get long sight lines but no storage. You need to plan and replan before even considering it.