I really like Dobies, but haven't owned one
At her age it's better to keep her on the skinny side - she won't be fully mature until around 18-24 months old, so keeping her light will put less stress on her growing joints and bones. At 10 months a large breed dog should look like a lean, lanky, gangly teenager
An ideal weight means when you run your hand down her side you can feel each rib, but your fingers don't fall into a groove between them. 70 lbs sounds like a lot more than a young female Dobe needs - how tall is she? If she has really thick bones than her adult weight should be around there, but don't worry about it until she is older.
If she really should be gaining more weight mac and cheese usually help, as do 'satin balls' - a google search will find a recipe. The weight gained will be 'fat', unless she gets the exercise it takes to turn it to muscle.
For a moderately built dog (any breed) 25" at the withers/shoulder usually is healthy at around 50 lbs. My Charlie is 24.5" and I've been keeping him around 47-49 lbs, though he'd proably look really good around 54 lbs. He's an active, athletic working dog who is better off staying skinny. My previous dog was 28" and I kept him around 60-65 lbs, but he had thin bones (genetics plus neutered early).
I'm not a vet, and no one can make a diagnoses over the internet - I'm just suggesting points for you to look into if interested...
