several problems with her arguement:
first: in europe we dont have mass shootings because either we dont have guns, or in countries like switzerland they are brought up with a high respect towards guns and dont advocate being trigger happy by saying "a bad guy with a gun needs a good guy with a gun".... swiss are also more disciplined... in germany gun owners need to own a licence for their guns and need to store their gun in a secure safe, making the gun inaccessible to pubescent teenagers or toddlers.

second: one successfull gun controll imposed in one state was making it slower to get guns, that in order to get your gun purchase done it takes 2 weeks. this addresses mental health because if you are currently mentally in a bad place and think of suicide or going on a killing spree, these thoughts are likely to go away after a day. that gun control was also not restricting the ability to get guns, but why need assault riffles if you dont plan on killing someone?

third: part reason why USA is so bad with mental health is also because much of it is the polices duty to address which get in return more than half of a cities budget while addressing mental health issues with what? guns.... they use guns to address mental health issues causing scenes of police officers threatening the ones in need who actually just need someone to talk to. so addressing mental health means also defund the police.