Nami mana issues

nami's mana cost seem to be really high especially for the amount of healing she does early game. i find that less than 4 minutes in the game i'm struggling to keep up with damage and i'm just waiting to get enough mana to re cast any ability. it's kinda a big problem considering she's not very tanky or has particularly good basic attacks so when she's out of mana she has basically no lane presence and i end up having to buy a bunch of mana and regen items as my first 4 items and by late game she ends up not having enough healing to make an impact. i've seen that it's been an issue for years but riot hasn't seem to have done anything about it