Tex - first off - I can not say how much I demise them retractable leads - They are a accident waiting to find a place to happen . Like G-Red had said .
As far as the biting of your daughter - I will guess that it's from what we call on here the Dobershark age - It has to do with there baby teeth and , it goes away with them losing them , they are also so young and use to ruff housing with there brothers and sisters and they play bite just to hard in there early life .
At sometime in all of our dogs life's , they have forgot there names ! lol Like G-Red said - E-Collar would or should help , I would never , ever , trust any of our dogs on total recall in a un-fenced in area , Them squirrels , rabbits , other dogs are a magnet for them , even the very best trained Dobers .
A dog run just don't get it for a Doberman - they need a nice sized fenced in area to run and exercise in , Over the years - every breeder we talked to required a fenced in area , just say 'n'
I would enroll Mesquite into some kind of puppy class , It really does help - mostly to help train you to train her , I have did this with every Doberman we have had ( since 1981 ) : ) Mr. Business was our first male we have had - he will be 5 in May - He was the most challenging Doberman we have ever had ! Yet with all the work we have done with him - he is outstanding . Training , training , training - I work with him everyday - just simple things then we have harder days of it - it pays in spades ! One of the best things when Mr. B was a puppy that we worked with was what they call set on the leash - or sit on the dog . this is were you hook them up to there lead and then sit on the lead - leave them some slack so they can lay down - they we not like this at first , but pick up quick - they will lay down and start the clock - start them out slow at first , maybe 5 minutes - if they get up before that time , then it starts over when they lay down again till they make that 5 minutes - this teaches them that this is your time . I did that trick every day when working at my desk - or watching tv - very simple to do and it works .
Like G-Red said - these dogs are Velcro Dogs - Remember this - they not only need attention -- they Demand it
Also - Mental work outs really wear them down lots quicker than running in yard - We have focused on Rally OB training , We had a morning class and a afternoon class here at home the other day- after we got done with the afternoon class the other day - Mr. B walked in , jumped up on the couch next to my wife and took a long nap - lol When I went in the house - Wife said wow , you must have really wore him out - it was all mental .
Take time and look over lots of treads on here with want others do with there Dobermans - Meadowcat - 79 , Lady Di , Rosemary do lots of OB and Nose work training - Chesa I believe does rat hunts with hers , Lot's of Show dogs on here too .
Best of luck !