Sandra, I had a quick look at your shop, and it looks like you have some great sewn items with a range of prices. IMO, the framed art would be the hardest to sell. From talking to my friends who do painting and photography, selling art is not a sprint, it's a marathon. Most people tend to take their time, think about it, take your business card. Sometimes they come back and make a purchase next year.
Have you ever visited any of the organizers mall show before?
Every show is different, but from my experience mall shows can be hard, because people are not there for the show, they are walking around the mall in a hurry (on the weekend). You have to push yourself to talk to people, to catch their attention. I always had to work harder at this at a mall show, than my regular craft shows.
I did mall shows for 10 years, 1-4 a year (2 was average), at different malls in my city. Each one was 6 days long, I wish we could of done weekends only, Saturday was often my best sales day.
But that was mall shows in my area - the ones in your area may be a bigger draw. Do you know how she advertises her shows? Do these shows have a good reputation? How many vendors will there be, and what kinds of goods will they have (for example Origami Owl, Scentsy, Watkins, or even what if there are 4 other sewers with similar goods?)
I would spend $150 on a show I had visited, or where I knew some of the other vendors, that they were pros that wouldn't waste their time. But it's up to you, whether you can afford to take the chance, spend the money if it doesn't work out. Shows are always a a gamble, even the best ones can have a bad year. Gathering as much info. as you can, is all you can do to help yourself make an informed decision.