Hopefully someone else will chime in here because I'm no expert on this sort of thing, but to me the TJMaxx pearls don't look like very good cultured pearls. They're heavily ridged and it looks like the nacre is thin and chipping. When you buy pearls, whether fake or cultured, what you want to look at is the lustre and color. And you want to look at the shape and whether they're evenly sized. Great pearls have a memorable glow and shimmer. I think one is better off having one exquisite pearl on a chain than a long string of bad-looking pearls.
I love the dress and I think it looks fabulous on you. I think you should be careful with the pearls because you don't want multiple strings detracting from your beauty in the dress. If it were me I would do a single strand of very good glass fakes, not too long. Or one very beautiful pearl on a long chain but only if you think you would wear it regularly in the future.
I have a long strand of fake pearls, and actually just bought (3days ago) the same kind you got at TJmaxx. I like the real thing better. I know the pearls are not even, but come on, if they were, the necklace wouldn't be at TJmaxx, and I wouldn't be able to afford it.
I'm not sure which one is best, but I think un-even pearls are trendy now, and they're a good way to:
1/ have cheaper pearls
2/ find a use for odd-shaped pearls
