YANBU- ignore them, people always make silly throw away comments, the reality would be very different. If they want to help, let them take her out in the day so you can catch up with sleep.
I wrote you a long post,but my tablet died before I could press post. It is quite late now so I will summarise the main points. IMO a lot of your dd's sleep issues stem from discomfort due to constipation (both my dd's have always had terrible nights when they were backed up and improve after mega poos, worse than teething).
Food diary plus food elimination (try cutting out dairy, wheat, gluten one at a time for 3 weeks at a time to see if it helps).
Also if you are doing BLW offer watery foods, lots of veg and fruit, stews are good, not too many beans and pulses (wind), cut down on pasta and bread (constipating), no red meat.
Up the lactulose dose, I was taking it 3 times a day in pregnancy.
Get a prescription for glycerin suppositories to help her move the compacted faecal matter (lubricate anus with vaseline). The lactulose would have softened the stool behind it so be prepared for poonamis.
If upping lactulose does nothing in conjunction with glycerin then ask GP about Movicol. Although untested on under 2's they can prescribe for babies (search on Google you will find examples).
I hope this helps, it is awful being sleep deprived.