My kid is so sad! Help!

Okay mamas. I need some help. This picture is my youngest daughter (5) at school. She’s been having such a rough time lately, so emotional, always sad at school, doesn’t want to play with friends, and this morning I got sent this of her just laying by herself playing with the grass. This is so not like her. I’m pregnant with our 3rd child, things have been tough because physically this pregnancy as pretty much crippled me to the point I can’t do much without extreme pain. So I know she’s worried, she’s said so. We’ve have conversations about our worries and feelings and if we are feeling worried or having feelings we need help with that it’s okay to talk to her teacher at school or mommy and daddy if she’s home. When she’s away from us all she wants is to come home and be with mommy and daddy which is so not like her! She’s been going to school since she was just 3 months old and has always been a social butterfly and very happy and very confident in herself. It’s breaking my heart to see my girl just sad and sullen all day at school. Her teacher said she doesn’t really enjoy herself at all. She’s not sleeping through the night, she would wake up and turn the light on in her room and stay up at all hours of the night while being so quiet we wouldn’t hear her. So now we’ve moved her into our room so we can make sure she’s getting the sleeping she needs. I’m at such a loss… my heart is breaking. And I want to help her. My hubby is going to pick her up and bring her home to me on his lunch break and we are going to keep her home tomorrow too and see if she’s just needing a break. But I also don’t want her to think that we will do that every single time she’s sad because then she will use that anytime she wants to come home. But my heart just can’t take this picture… I blocked her face out for safety but her expression is that of someone who is sad and pondering.