I am very surprised to see all these people saying that if someone tests a person's muscle tone that "they are fine". There are other things that could be happening as well, not just muscle tone issues. 'How' did this doctor test muscle tone? How do you know that this child is not having pain when trying to use her muscles? Did he do extensive enzyme testing?
I have a 15 yr old daughter with adrenal disease (low adrenal hormones). Her muscles have slowly wasted. She cannot carry 10 pounds. She has sleep issues , chronic fatigue, low blood pressure,PAIN IN HER MUSCLE when she has used them a little, and much more. She is smart enough to know that certain actions cause pain, so she doesnt do them. As a baby,she met every milestone ahead of schedule. But she went into shock at 2 when she had a kidney infection, and now she would have probably been labeled ADD if I didnt have the medical research to push that her concentration issues are blood sugar related. She has seen at least 10 doctors in the past 5 years, ...a large majority told me she was fine. They take a blood test and tell me she is fine. When she runs, she passes out cold. That is not fine. Her glucose tests out "fine" on blood tests, yet I see her blood sugar drop so dramatically she looks like she is going comatose.
I guess the point I am trying to make here, is that you really don't know if that child is fine. She can't tell you. But behavior and symptoms speak volumes.
Fifty, sixty years ago, those milestones in the medical books were pretty much dead on for healthy, normal children. They hit them. The reason so many people say they aren't valid anymore is because most of our kids are so sick, and many kids don't hit the milestones like they used to. Rather than admit that we have an epidemic on our hands, we simply just rewrite the standards and push the milestones out farther. In just the past 40 years I have seen a huge change.... it use to be that one child in the entire school had a food allergy or health issue, now 1 out of 5 kids has some kind of health issue. Does it not seem that every family you know has a sick child in some sense? It just was NOT like that when I was younger.
My third child had some issues as a baby, First i will say I had a yeast overgrowth while pregant. Baby was born with a very large distened belly- in which they told me she was fine. I always worried about that. Not normal in my opinion. she didn't hold her bottle, when she finally tried, she would try to reach for it and knock it out of her mouth. She didn't babble. She didnt crawl. She never cruised furniture or used a walker. She finally started walking, late. She would not attempt any scentence longer than 2 words or would not attempt any word longer than 2 syllables....until she was 2 or 3 years past that milstone mark. At 8 months I told the doctor, and freinds, I was concerned about her. Hubby and freinds said she was fine, and the doc called her name, she turned and looked at him, and he said "she's fine". That is how he evaluated her.
Three or four yrs later, I was reading some medical literature for a freind, and realized in hindsight, that she had every single symptom for autism when she was a baby. I never pursued researching it because so many had told me she was 'fine'. She is 10 now. She still has some issues.....not very savy on social cues, hard of hearing, allergic to milk products, belly still distended, Keeps an illness for way longer than is normal, has a hard time writing without using large letters (that is nervous system issues still showing) , and is now showing signs of muscle problems. (Pain and weakness). She wakes with pain in her legs, arms. I am fearing that when puberty hits, she may show adrenal hormone issues as well just as my other did..
So I say, trust your instinct, stay on top of it, do your reasearch, the web is chock full of answers but it can take a long time to find them. Keep researching. The best specialists are very few and far between, but they do write books and medical literature,much of it online, and will know far more than most local 'specialists'.
I recommend you go on Yahoo and research HORMONE and ENZYME deficiencies in tandem with muscle pain or muscle weakness, which are at the heart of many, many illnesses today. Also research floppy baby syndrome. I know you said she doesn't seem floppy but she seems to be having muscle issues anyway, so do research it. I lent out my medical file to a friend but I think i remember floppy baby is an enzyme deficiency. Potassium is key to nerve and muscle tone as well. Potassium is an electrolyte and electrolytes are controlled by hormones (cortisol and aldosterone).