Hi! Not sure if it's the same thing (I don't know what SNS means!) but when DD was born, I didn't get my milk until day 8 and until then I used a lactation aid which was a little tube attached to a syringe. I would put formula in the syringe and the tube on my breast so when she would suck, she would get formula from the syringe as well as stimulate my breast to produce milk.
It was quite a lot of trouble to manipulate, and my DD was young so not very mobile, I can assume with a 7 month old it must be quite a challenge!
One thing that helped was using some scotch tape to tape the tube on the top of my breast so that it would hold in place on it's own, and I would put the syringe on the top of the couch behind me. That way I could use both of my hands to install DD properly so that her sucking would start ok.
Not sure if this helps or if we're even talking about the same thing but I thought I might post just in case. I also think I saw a video on Dr. Jack Newman's website about this, you might want to check it out as well.
Good luck!!