This is a pattern I used earlier in March to make my daughter a dress. It has long ties for shoulder straps that tie in the back. for these, I measured each of the girls with the dress on to get the strap lengths and length of the total slip. They were really fast and easy to make! This dress always looks so comfortable to wear.
The back of the original dress calls for three rows of elastic, but I just did one and changed seam allowances a little because I spaced doing that while cutting the length. PREGNANT BRAIN!! it's a real thing, it HAS to be!