Maithali is scared for both Myrah and Rudra...thats what her actions tell me...her talk with samrat about rudra's remarriage only came after she saw rudra getting affected by Myrah in traditional clothes...Maithali knows he was searching for Paro in Myrah...as he does every single time they interact with each other...thats why at first he wouldn't look into myrah's eyes...
Maithali may seem interfering but her only objective right now is to save rudra from a lot of pain...
And the only reason she's even trying to interfere in rudra's life is because he has given her the right...he didn't get angry at her he knew why she did it...she loves rudra and dhruv both...so i don't think comparing her to mohini is appropriate...