I had an enlarged spleen only once (that I know of) and that was when I developed ITP (thrombocytopenia). If she has that, her blood and platelet counts will be low because the spleen is destroying platelets... it's a rare disorder and unlikely but if she is at anemic it could be something to give a quick look at.
I hope she feels better soon... Poor kid.
Thank you for replying. The mono was negative but her Free T4 is low. More testing. Thanks again. I don't think that swollen spleen is from gluten. I think it has something to do with whatever she is fighting. I hope.