Mamabear try and find one of the light weight machine. all the different machine seem to have a light weight one. I have seen on CL and at shops. Kenmore has one and they run about 100.
They maybe used but they still sew for what you want it for . I also have the same machine you have and it is heavy to carry.There are singer and brother maching that are also LW. Just check around you will find what you want