Oh dhokla is the perfect pregnancy snack honestly, steamed and light, not fried. I had it loads in my second trimester. Just make sure its fresh and not too spicy in the tempering.
Yes totally fine, its steamed so its light on the stomach. Fourth month you usually have more appetite anyway. Just keep it fresh and homemade if possible.
Yaar dhokla was my go to in pregnancy, actually it didnt give me any acidity unlike fried snacks. Soft and steamed na, very easy on the tummy. Go for it.