My dog has just had a litter of puppies and I need some help!!?

I have a pet mastiff and she is only 12 months old she has just had a litter of puppies... I know she is far far too young but it was total on accident!! I left her in the care of what used to be a good friend for a few hours and he was very careless we have had a mive fall out over it and no longer talk!! Any way to get to the point Im a bit concerned she hasnt been a very attentive mother from day one she had a litter of 8 big chunky healthy pups the 1st three died I think it was because she neglected them (they was the 1st 3 born) it was early hours in the morn when she had given birth( aprox 4am) I woke up around 7 am and she was still in labour having more pups to my horror I saw the dead pups and also a pup still in the bag that was half licked of and she wasnt bothering with any of them I dont know how I managed it but the pup that was still in the bag i opened my self and brought the pup back around to life and helped her give birth to the other 4 she then started to show a bit of interest to the pups but she dosent seem very bonded with them she WILL feed them but only when it suits her she has never picked them up in her mouth she just dosent seem botherd shed rather sit outside and sunbathe than feed her pups for the last 3 weeks I have had to really clamp down and force her to look after them (in a nice way) it has been extremely hard work!! I just want to know why my dog is acting like this? Is she depressed? Has she neglected them? But if so why is she feeding them? Is it her age? also when is it suitable to start weaning the pups on to proper food and water? I cant expect to get the signals from the mother because I dont think she,s doing her job as a mother properly to begin with!! Can someone please help me?