How can I support my mother and sister from afar?

Assalamualaikum! I didn't expect to be asking this, but I could really use some guidance 😞 I'm the eldest of three girls. My mum had our youngest a bit over a year ago and now lives with my dad and my middle sister. I moved abroad four months ago to continue my studies. Since the baby arrived, my mum has been under a lot of stress. Before I left I used to speak to her every day about whatever was worrying her. Mum and my younger sister argue a lot - things like school, exercise, computer games 😅 - normal teen stuff. I used to try to listen to both sides, remind them to put their trust in Allah, and help calm things down. When I couldn't solve it, I'd try to distract them so the tension would die down. Mum has a pattern where she spirals emotionally; she ends up blaming herself or thinking everyone dislikes her. It's been like this for as long as I can remember but it's worse since the baby. It pains me that she feels so low. Usually when I raise issues about my sister it leads to Mum feeling bad, and if I bring up Mum it affects my sister too. Dad is away working most of the day, so the house feels empty with just Mum, the baby and my younger sister. Being away makes it much harder to help - when I was home I could take the baby for a few hours or sit and talk with my sister to motivate her. Now I feel helpless watching them clash from a distance. Alhamdulillah we are blessed in many ways compared to others, but I want our home to be peaceful. I'm exhausted from being the family comforter for the past five years, yet I keep doing it for the sake of Allah. I just want practical ways to support them while I'm far away. If you have any advice, duas, or short hadiths I can share with them, or tips on how to communicate better from another country, please help me. JazakAllah khair for reading, and sorry if this was a bit rushed 💗