Student finance - parents not legally separated?

My parents separated six months ago. I am currently applying for loans with Student Finance NI and an NHS Bursary to study Nursing.

Obviously, I now reside solely with my mum and so the household income has dropped. I know I have to fill out separate forms for that change in income to be addressed.
However, on both the student finance and NHS bursary applications, it asks for evidence of my parents separation, for example a solicitors letter. Obviously, with it being a fairly recent (though I stress it is permanent) separation, they haven't looked into solicitors yet. However my mum is claiming benefits for herself now as a single person and adjusted child tax credits as a single person for me and my brothers.

So I'm a bit stuck as to what to do - how can I provide evidence without a solicitors letter? Anybody been in a similar situation?

I know sfe accept a council tax bill as evidence that your mum lives alone so try that ?

We don't pay council tax in Northern Ireland - but you saying that I might look into seeing if my mum being the sole tenant on the house we rent being evidence - thank you!