My best gf had her twin girls at 35 weeks gestation and both were over 6 lbs each, so a very good size for twins! She is slim and a little taller than me (I'm your height). The girls spent a little bit longer in hospital due to their early arrival, but only in the SCN for a few days (not NICU). No issues at all and were home after just over a week, from memory.

She recovered well (had a vb), but had some issues with her tummy muscles splitting quite badly during the pg that took a lot longer than a normal pg to knit back (and I don't think they did so properly for years). That was down to the size of the girls and her belly at the end.

GL!