In the end, the final decision between 200 cc and 250 cc (or 300 cc) is going to boil down to what you like personally. You will have to make the final choice on that one, because based upon the information and pictures you have provided either size will look great on you. You are a "tallish" girl, at 5'7", so you have some leeway to choose a larger implant and still look great, or a smaller implant and still look great. It's hard for us here online to make specific recommendations about implant sizes without actually examining you, but I can make a few general observations that hopefully can apply to your situation and help you.First, I see from one of your images that you are considering anatomically shaped implants. I think that's a great idea. I love the shaped implants, especially for slender girls with not a lot of breast tissue who specifically want a "natural" look to the breasts and want to avoid an overly rounded, unnatural upper breast contour. The one thing that I find in my own patients when we are choosing between two sizes of shaped implants, is that more often than not, if we "cheat up" a bit and go with the larger of the two sizes, we wind up being happier. That's because the volume in a shaped implant is distributed differently than in a round implant, and the impact of the extra volume is very subtle between two close sizes. You are trying to decide between a 200 cc and a 250 cc implant. That is a 50 cc difference - just shy of a "double shot" in volume ( a one ounce shot is 30 cc, so a "double" is 60 cc). That's not a huge difference, and most of that winds up in the vertical dimension in most shaped implants, meaning that it is distributed more toward a slightly longer shape vertically, as opposed to a higher projection in the top of the breast like we would see with round implants in the same situation.This brings me to the next point. You have breast fed 5 children and lost a lot of weight, and you say that your breasts are deflated and "all skin." Most ladies I meet like that have some laxity in the breast tissue, and even though your nipples appear to be well aligned and you don't need a lift, I'll bet that you have laxity of the lower breast tissues, and you might even have some "glandular ptosis," or drooping of the bottom edge of the breast gland below the inframammary fold. Given the way that shaped implants work, the majority of the volume and projection is in the lower pole, at or even slightly below the level of the nipple. Thus, the implant itself has the effect of pushing the nipple upward and outward, without creating a large amount of similar projection in the upper pole like round implants would. This effect will be slightly more with a slightly larger implant, and in your case, that may be worth considering if you have the kind of laxity I have described. Again, this is one of those considerations that a personal exam is helpful with.Another thing to consider is that with shaped implants, much more than with round implants, we approach the planning from a "dimensional" as opposed to a "volumetric" perspective. This means that to the surgeon planning the operation, the dimensions of the chest and breast tissue envelope and how the implants under conderation will fit and interact with them are much more important than the actual volume of the implant. This is still important in the case of round implants, but not nearly as important as with shaped. Thus, you may find that your surgeon has some input into the optimal size of implant you should consider too, based upon the measurements he or she has taken of your chest and breasts, and that needs to be considered as well. You said they recommended 250 - 300 cc, and there may be a reason for that.Lastly, I realize that you are gauging the appearance of your breasts with each size of implant by trying on implants in your bra and looking in the mirror. Unless you are using specially designed sizers, this may be a bit of an overestimate of the size, and more importantly the projection, of the breasts after surgery, and even if you are using sizers it still may be an overestimate depending upon how the sizers fit over your natural breast tissue. This is because once the implants are in place in their pocket, as opposed to just sitting on top of your natural breasts and just sticking out there, especially if they are placed in a submuscular or dual plane position, they will not project as much as what you are seeing now. The good news is that you will look great no matter which size you pick! The bad news is that you have to pick, but hopefully we will give you enough information that you can add that to your consideration and come up with an educated choice. I can tell you just for perspective that in my own practice, especially with the shaped implants, the average size we use is in the mid-300's, so at 200 - 250 cc on a 5'7" frame, you are not going huge by any stretch of the imagination. Just keep thinking about it, ask yourself if you would be more disappointed if you were too big or too small after surgery, and lean on your surgeon and his or her staff to answer any specific questions you have left before surgery. Try not to worry too much about this though, I think the hard part has been done, and you'll look great with either size! Best of luck.