Many meds are the same dose for a 125lb woman and a 200lb man.  125 lbs
isn't emaciated.  You're a grown woman not a child (dosing can sometimes be
different for children despite weight)

My husband and I have been rx'd the same dosage for many antibiotics, nsaids
and supplements and he weighs 190lbs and I'm 120lbs.  In fact, I was taking
50mgs Vioxx and he was only taking 12.5 mg.  It depends on how much pain is
involved.
My father who is obese isn't rx'd a higher dose of a nsaid than I am even
those I weigh over 200 lbs less.

I agree with the other poster, you've diagnosed  yourself (mis-alignment;
cartilage breakdown and missing; bone slipping out of knee joint) and that's
impossible.  An orthopedist who has many years of experience can't even
diagnose you without running tests.  You need x-rays and possibly a ct or
mri to see what's really going on.  Find an orthopedist.  The orthopod will
determine what's going and what treatment is needed if any.

Glucosamine/chondroitin is supposed to be a preventative... it won't regrow
cartilage- it would be a miracle supplement if it did.
You've had this same pain for 10 yrs and 100 mgs of ibuprofen (1 tablet is
200) stops the pain? My 8 yr receives 200 mg ibuprofen when needed... that's
the dosage according to her weight-70 lbs.

Doesn't sound like there's too much of a problem and the situation is hardly
emergent.  Hope the doctor takes you seriously.  When I've gone to the
orthopod for my knees, I had problems for weeks and not years and even then,
physical therapy was one of the first treatments along w/ibuprofen 800mg 3 x
day.  If that worked, there was nothing else to do at the time.... I don't
know if I'd waste my time if 100mg ibuprofen solves the problem... good luck
finding a doctor