You can address the issue with the file clerk, the lawyer, or perhaps even the file clerk's mom, but only if you have a personal relationship with the file clerk's mom.
If you address it with the lawyer, I would make the conversation entirely fact-based and your lost productivity only, not the file clerk's absences. This is the path I would choose, if I addressed the issue at all.
There's a reason the file clerk has mental health challenges, and there's a strong chance that reason is her own mother, so going to work and having possibly to face or deal with her own mother may be the real problem here.
And that's why you may not want to address the issue at at all, because if you address it, that senior paralegal may target you instead of her own daughter.