He has made remarkable progress has baffled doctors who expected the youngster to still be an induced coma, which he came out of after only four days.
Archie from Hindley, Greater Manchester, who was initially sent home from hospital when doctors dismissed his headache and aching limbs as a simple viral infection, is managing to walk with the assistance of a frame.
Archie's symptoms began when he returned from school on March 19.
Speaking of her son's illness, Ms Musgrave said: "It all happened so quickly. Archie kept telling me he had sore legs and a headache and just from knowing the signs of things I said to my husband that we had to get him to hospital."
He was taken to Wigan Infirmary before being sent home, with his parents being told to bring him back if he got any worse.
Ms Musgrave said: "When he was being sick during the night I thought it was a bug but then first thing in the morning I noticed a little rash, like a purple bruise. I knew that wasn't right. I looked again at his body and the rash was coming out. We got him back to A&E and doctors and nurses were all rushing in to treat him."
"It was awful, the worst time of our lives. It was just a shock. You see things like this on TV but you don't ever think your child is going to get it."
Speaking with the Daily Mail about her son's recovery, Ms Musgrave said: "He's doing as well as he can be. The doctors and nurses have been amazed, they said some children who have menB are still in a coma at this stage."
"Everything is under control and he is doing well. He's on a lot of antibiotics as well and we don't know how long he will be in hospital for. It depends how the infection is treated but things are looking promising."
"He's able to sit up now for a bit but then he wants to lie down again because he is still quite weak. He's trying to take a few steps on his little frame. He can't really do it yet but it just shows how much he is fighting and how strong he is in trying to get where he wants to be. We're just so proud and overwhelmed with all the support."
Hundreds of local residents, including a number of rugby league stars, have rallied around the family on social media using the hashtag #Pray4Archie.
Ms Musgrave is also urging parents to ensure their children are vaccinated against menB, saying: "I cannot express enough how important this is. Children are only immunised against it automatically if they are born after 2015."
"If they were born before that they need to go and get the jab done. I want everybody to know about this."