Fun things to note:

Stimulating the nipples leads to contractions. After the baby is born you can use that to tighten her vagina.

Licking her clit and work two fingers into her. Keep her wet and stretch her out while you lick. Work up to stretching her a lot.

Notice that you'll clear her sinuses when she cums.

Cum in her often in final few weeks. All this will help the labor.