You'd have to ask her constituents. But what can any individual MP from a party that's not - and in the case of the SNP, can never be - in government in Westminster actually do? I think they have been (when allowed the opportunity) quite good at doing the oppositioning that Sir Starmer is too timid & reticent to do, but as far as why they're elected & what they have been sent to Westminster to do, there is literally no way within the confines of the UK's broken system for them to further that aim, never mind achieve it.
So yes - arguably pointless, & I think there's certainly a discussion to be had that they should follow Sinn Fein's example and not take up their seats.