I'm not sure if this is old-news repeat advice from what you received 10 months ago but...
Is she taking any nap during the daytime? If not, I would encourage one by having very vigorous physically exhausting play for at least 45 min - 1hr in the am, followed by having the house set up for very calm, quiet time....no TV, radio, lights, etc....hopefully she will get a small nap. This may take a while to get her into a routine.
Once she has had some daytime sleep, many kids can inwind and sleep longer/better at night.
As for sleeping longer at night....is she getting enough physical/mental stimulation during the day and afternoon? If not, she likely doesn't need as much sleep. Do you notice that after a few hours at the park, beach, long walk, gymnastics center, open play at a jump-house, kids play center, pool, etc that she is tired and is more likely to doze off? If so, that means that she does and will need sleep when actually tired or wor out....meaning there is nothing wrong with her to require meds, etc...she might just need more exercise, both physically and mentally. After you have really worked on wearing her out so that she really needs the sleep, she may develop a nice pattern and routine of sleeping more.
If she has days where she doesn't need/want to sleep then get her used to 'quiet time' or dont use bedtime or naptime terms, just say it is her 'rest time' in which she can sleep OR play something quietly on her own (in a child safe room), ie coloring, reading, dolls, listening to soft music, etc...
Just some thoughts....hang in there and good luck!