Not so much from a lore perspective as I know I would get some bit wrong, but more from playing one.
First this can just be your reason it has powers, so awakening the item is like making a relic. It grows as you grow and are able to tap it more.
Try not to make it a "deus ex machina" or the centre of RP plot. Yes run story lines to find out more, involve the item but make those involved the focus. Maybe even have moments when she does not have the item. Give it some weakness, make it about the character and how they need to act, perhaps even give it RP flavoured side effects.
Give it a personality, the talking sword, the haughty wand, your nagging mother in the staff. This also helps locking it into what  it will and wont do for you.
Also consider that the item is just a focus and that the real power is within your character, they just think it is the staff?
Have fun with it, use it to enhance your RP and avoid making it the centre of RP.
First this can just be your reason it has powers, so awakening the item is like making a relic. It grows as you grow and are able to tap it more.
Try not to make it a "deus ex machina" or the centre of RP plot. Yes run story lines to find out more, involve the item but make those involved the focus. Maybe even have moments when she does not have the item. Give it some weakness, make it about the character and how they need to act, perhaps even give it RP flavoured side effects.
Give it a personality, the talking sword, the haughty wand, your nagging mother in the staff. This also helps locking it into what  it will and wont do for you.
Also consider that the item is just a focus and that the real power is within your character, they just think it is the staff?
Have fun with it, use it to enhance your RP and avoid making it the centre of RP.
Char:Â [Nebula Stardancer] Â FC: [East Eerie Trading Co]
Link Shells: [Hugs & Cakes] Â [Witches' Wyrd Web]
