Unfortunately, meddling begins in pregnancy and has no definite end. I know many people whose children are all grown adults, and who still receive meddling "advice" on their relationships with their children. You have to develop a spine and work on your approach to meddlers. Pregnancy, while not a convenient time to deal with this, is your #1 opportunity to develop these skills.
The first thing to keep in mind is that you are the parent and you do not need to JADE (justify, argue, defend, or explain) your decisions.
The second is that humor and beandipping may be two of your best friends.
For the first situation, I would laugh and say "Wow, let's not go there. Bean dip?"
For the midwife, "I have it covered, thanks. Bean dip?"
Start out pleasant, but if she continues to cross boundaries, you'll need to get more firm.