Pose 16 has the arm of the sim on the back of the couch. I created a pose to fit on the three heights of couches, 16low, 16med, 16high. However all couches are not exactly the same height so the pose may not be perfect.

CC Seen In The Pics - you may choose your own

Footstool
https://www.thesimsresource.com/downloads/details/category/sims3-objects-furnishing-comfort-livingchairs/title/christmas-2011-foot-stool/id/1118832/

Emma Couch
https://www.thesimsresource.com/downloads/details/category/sims3-objects-furnishing-comfort-sofasloveseats/title/emma-living-room-sofa/id/1245054/

Codes

a_bmit_pregportrait1 (goes with pose 2)
p_bmit_pregportrait2 (toddler goes with pose 1)

a_bmit_pregportrait3 (pregnant sim, goes with pose 4 and 5)
a_bmit_pregportrait4 (adult sim holding toddler pose 5)
p_bmit_pregportrait5 (goes with pose 4 and 5)

a_bmit_pregportrait6 (pregnant sim standing)
p_bmit_pregportrait7 (toddler standing on foot stool)

a_bmit_pregportrait8 (goes with pose 9)
p_bmit_pregportrait9 (goes with pose 8)

p_bmit_pregportrait10 (toddler kissing stomach of pose 6)

a_bmit_pregportrait11 (pregnant sim)
a_bmit_pregportrait12 (adult looking at toddler pose 13)
p_bmit_pregportrait13 (toddler pose goes with 11 and 12)

c_bmit_pregportrait14 (child goes with pose 6)

a_bmit_pregportrait15 (pregnant sim sitting on couch, goes with pose 16 and 17)
a_bmit_pregportrait16high (sim sitting to left of pregnant sim, toddler sits on lap)
a_bmit_pregportrait16med (use on medium height couch back)
a_bmit_pregportrati16low (use on low height couch back)
p_bmit_pregportrait17 (toddler sitting on lap of pose 16, touching stomach of pose 15)
c_bmit_pregportrait18 (child sitting next to pose 15)

a_bmit_pregportrait19 (goes with pose 20)
c_bmit_pregportrait20 (hugging stomach of pose 19)

a_bmit_pregportrait21 (pregnant sim)
a_bmit_pregportrait22 (adult sim holding toddler)
p_bmit_pregportrait23 (toddler, goes with pose 21, 22)

Credits: spacesims, TheNumbersWoman