Hello my 8 year old has not grown in height or weight and shoe size in nearly a year

Last year early December I took her to the doctors as she was always pale tired and dark circles under her eyes they took her weight, height and asked us to come back. On February but cause of Covid it got cancelled. She seemed a little better so I left it.
But in the last 6 weeks or so she seems to be getting worse and complaining of back pain and feeling sick constantly.
So I took her back in this Friday and they took her height and weight and found it’s not changed the whole time and also her feet have not grown since last august. They have taken urgent bloods and we are waiting for results on Monday.
I am going out of my mind worried what it could be.

She was examined and he found no obvious lumps and bumps.
Can anybody help with what this could be or have had the same thing?

Right now the best advice anyone can offer is to allow your Doctor to be your guide. There are many reasons that medical conditions can occur. Try to not go randomly searching on the internet for diagnostics as that alone can make you crazy with unneeded worry. Unless her situation is critical of which she would be in a hospital her doctor has decided to rely on tests and as hard as it is they take time. The hardest thing for any parent is to have a sick child.

If need be, I suggest looking for a second opinion from another doctor too.