What sentence should I expect my g/son to get for distribution of 5 counts of marijuana?

in the state of Virginia he sold to his g/f's friends bother who was an informant.The informant always asked him for more than an oz which he usually didn't sell but he accommodated the informant.He has had nothing but trouble since he started dating this girl..He has an assault charge and making threats on a public airway 1 yr ago against her ex boyfriend cause he said she was pregnant with a ****** baby.Next she had his baby and they both were smoking pot heavily and on Nov 11 the baby was found dead in the bed with them and she was only 7 weeks old.The investigator said they found evidence of drug use in their apartment.The autopsy on little Kallie said "cause of death undetermined: co factor sleeping with parents.I think they rolled over on her and she died..This was so devastating..she was so sweet..My g/s and his g/f were devastated as well and the commonwealth attorney is aware of this situation but they didn't charge them..She was also charged with conspiracy to distribute cause she was in the car with him all 5 times.They are 18 and 19 and she is pregnant again and they are living with her father..it was a long time before I could even look at them...but the pain is easing...With all the history on these two even though she has no criminal record what do u think the sentence will be..My g/s mother died of a cocaine overdose 6 yrs ago and his dad is a deadbeat who acts like he could care less.He suffered years of verbal and one incident of physical abuse from his step mother...I am not condoning what they did.i had warned them to stay away from drug and to not sleep with the baby.She never appeared to bond well with Kallie..She is just sorry and lazy and he is lazy too.These felonies will ruin their lives.What factors will the commonwealth attorney take into consideration.They both are going to plead guilty and throw themselves at the mercy of the court..it was less than a pound..Thanks