I recently started a Shadowheart Origin run and wondered what to do about her abysmal charisma as well. In the end, I granted her 10 points instead of 8 and either weasel around the charisma checks by using insight checks or the tadpole, or let Astarion, Gale and Lae'zel deal with social situations which require their specific proficiencies. It's nice to have a character who actually has a chance of failing dialogue checks for a change - and it's also nice to play the tadfools more as a team outside of combat.
