Yay! Let’s start with actual maternity dresses and then look for stretchy jersey dress styles that aren’t maternity but might work for you. (I couldn’t find anything for my baby shower so I ended up wearing a very forgiving jersey dress and it worked great.)
I like this H&M MAMA chiffon dress ($35), especially in coral.
ASOS has lots of good options. This midi length dress is on sale for about $30-$40. This pink wrap dress is one of my favorite options for you (it’s $52). I kind of love the super sexy fit on this dress ($37). This swing dress is pretty ($52). I LOVE the monochromatic floral print on this midi dress too ($52). If you want a softer look, this gray/peach lace dress is sweet, but a little over your budget at $103. This cobalt midi dress is simple and the bright color is fun ($33). Last, this pink/red floral dress is stunning and is just $84.
Now for non-maternity ideas:
This T-Bags Los Angeles jersey maxi dress on Gilt is $99 (from $202) and has a high empire waist.
This empire waist jersey dress from Boden ($58 from $78) comes in several different prints and might have enough stretch to work perfectly, especially if you size up.
Maxi dresses are always a really safe option. If they don’t have a zipper, you’re probably good to go. This Rhyme Los Angeles dress has a great print ($98). This Tart dress ($101) is really stretchy with 5% Spandex. This LA Made cami dress is just $54 in a great peach/coral color.
Swell has some good maxi dresses too (at affordable prices!). This pink one is forgiving, though it may be more casual than you’d like ($59.50). This Minkpink dress ($97) is a fun, bright print and the empire waistline is great.
Revolve Clothing has tons of jersey items too, like this Bobi tank maxi dress ($62). I also love this stretchy, multi-wear dress from Kamalikulture ($96)—it is black though! I had to include one black dress. I couldn’t help it. :)
(Speaking of black dresses, if you want to do something kind of AVANT-GARDE BABY SHOWER, this Narciso Rodriguez dress on RTR for $85 is so good.)
Anyway, I hope one of these catches your eye! If nothing looks good to you, let me know and I’ll keep searching. I hated shopping for my baby shower dress so I feel you on this one.