Stronglifts and being able to fit into Wedding Dress

Are you eating for a caloric deficit or at maintenance? I don't know if anyone can really tell you since all bodies are different, but if you are eating at a caloric deficit it seems unlikely to happen, since gaining muscle usually requires a lot of food (providing one is not overweight).

You should have another fitting before then, right? That should give you a good idea of where you are at and how much you are changing.

Your body comp may change a bit, so the dress could be tighter in some spots, looser in others. More likely a little looser all over. Lifting and eating at a deficit definitely should not make you any bigger, it should help you to be tighter and smaller.

I would also maybe take a couple of rest days right before the fitting and right before the wedding so you are not holding as much water. Awesome measurements by the way!

Oh, and yes, you will "tone up" at a moderate deficit. Getting strong is just a fun side effect

Yes, SL will help you "tone" if you are in a deficit. Your muscles will not get physically bigger, but they will seem more defined as you lose the fat. You will get stronger but smaller overall at the same time. As long as you are in a deficit.

1 - you can't "bulk up" while dieting...if you could, that would also mean you could get fat while you're dieting...it's mathematically not possible.

2 - SL isn't even a bulking program, it is a strength program.

3 - "Bulking up" is a deliberate act; it doesn't happen accidentally

4 - Most women do not have the genetics to "bulk up" without a lot of help by way of supplementation and drugs

5 - Most women you see who have a little muscle and have some muscle that "pops" are actually smaller than their female counterparts of the same weight...because muscle is more dense than fat...therefore you would actually be more compact.

You could do each of them 2x a week to mitigate fatigue. I do SL twice a week and have had dramatic changes from losing inches. My other favorite is yoga and I do that 2x/week.

Just give yourself 1-2 decent rest days and I think you can incorporate both.

Weight lifting with a program like SL is supposed to make you stronger, not help you lose weight or bulk. Stronger says nothign about how you look. Google weight lifters, as in e.g. participants in the olympics. Every single one of these women, in all categories, can lift impressive amounts. Some are lean, some are definitely overweight if not obese, and there is everythign in between. They are all incredibly strong.
If your goal is to fit in your wedding dress and look leaner, you were seeing results so far, and you also loved what you were doing regarding classes, then drop SL, and keep doing what you were doing. Why change somethign you love and that works? If you got interested in free weights and want to see how this goes or want to be able to lift heavier, then continue with SL and move your focus there, do not try to just add it on top of everything or you will be injured by the time your wedding day arrives.
But do not choose a program, any program, as a sacrifice because you expect it to work miracles and change your body in a few months.
If you really want to keep the classes and experiment with weights, maybe look into some other program, or get a personal trainer, explain your goals and preferences and seek advice?

Listen...just search for the thread "lifting made me supah bulky!" A lot of the women on the thread lifted on a deficit or maintenance, they all look amazing and for the most part-smaller.

I lifted on a deficit and only got smaller. It's just science. You're not going to grow big muscles this way. You will just look a lot better than if you had not weight trained (in my opinion).