Protein in urine, and low platelet volume

Hi everyone
Been a very long time since I have been here, but I have a concern about my daughter, and my husband chooses not to talk about it, because it makes him upset as we are both worried and stressed.

Back story:
Back in September, our 4 year old complained that she had a sore back, so I assumed she had developed a UTI, as that is what my symptom is whenever I get one.
I work at a dr's office so I took her urine sample to work with me to do a dip, and it came up that there was protein in her urine but no bacteria (so no UTI). I took the sample to our doctor and asked her to dip it and send it away for a urinalysis. Their dip came up negative, but I insisted they send it, so they did. It came back with protein and blood in it, but still no bacteria. They repeated her urine sample 3 times, and still .. Blood, Protein, no infection. Our doctor then referred us to a paediatrician, who we saw 3 weeks ago. She assumed it was a common condition called 'orthostatic proteinuria' where, when a child is active, protein sometimes leaks into the bladder, but it's not a big deal. To be sure, the paeditician ordered an ultrasound of her kidneys, blood work, urinalysis, and a 24-hour protein collection.
2 weeks after after testing, we booked our follow up and the doctor told us that the ultrasound was normal (YAY!!) BUT, her protein was through the roof in her urine, and her blood work came back abnormal. She told us that as soon as she received the results of the blood work, she called a paediatric nephrologist (kidney specialist) and told him the results, and sent 'an urgent referal' to the Children's Hospital and he would be performing a kidney biopsy. All I heard was "through the roof" "abnormal" "urgent" and "biopsy" .. Never once did it cross my mind to ask what was "abnormal" about her blood work.
I left the office completely dumbfounded that something as simple as a suspected UTI could turn out to be something 'urgent' and needing to be sent to a specialist. The entire way home, I was kicking myself for not asking about the blood work, so I drove to my doctor's and asked for a copy of her bloodwork. Turns out, her MPV (platelet volume) is very low. Of course, I'm not a doctor, so I chose to google "low MPV" and it turns out that it is caused by the bone marrow not doing it's job, and in most cases, it caused by 'cancer of the blood' (Luekemia)
I get home, to find a message on my answering machine saying that our appointment at the children's hospital is this Monday.
Now, here I am, not having slept in days, and still 2 sleeps away from Monday, and I can't stop thinking about what this doctor is suppose to say. Apparently he is an amazing doctor, a professor, and the chief of paediatrics and paediatric nephrology, but I'm am still SUPER worried that it could be something VERY serious.
I should have just stayed away from Google!
Anyways, does anyone have any experience with high protein, and low platelets that can offer some insight, and tell me I'm over reacting??
I'm going crazy here thinking about it, and I don't know what else to do!

Sorry for all of your sleeplessness and aniexty i can only imagine. I only know a little something about low platlets there are so many causes. However it concerning that you mentioned her bone marrow is not working properly and that i recall being sent to a blood doctor (Hematologist) to have a blood work-up where they check any and everything causing platlet counts to drop.. Cancer is one , lupus, all types of hepatitis etc. HIV all sorts of things..I understand how concerning this must be for you..Praying for your LO and sorry I can not be much help I do not want to say things to worry you more- If i did that already I' am sorry

Quoting Barnett Babies:" Sorry for all of your sleeplessness and aniexty i can only imagine. I only know a little something about ... [snip!] ... for your LO and sorry I can not be much help I do not want to say things to worry you more- If i did that already I' am sorry"

I don't think it's possible to be more worried then I already am LoL
She has always been my sick child. She gets pneumonia twice a year thanks to the lung scarring from when she was born. She was 5 weeks early and born with a lung infection, so from day one, I have always been concerned about her health. Just now, it is starting to get very concerning when an urgent referral to a specialist is in the picture.