Hi, my question is about whether or not I should be a trustee of a friend's trust?

My friend Mary 64 yrs old, lived in NZ, NZ citizen. She sold her property last week. The property was under her family trust where she, her 2 sons are trustees in the trust. Both her sons are working in Australia. She worried that her sons will be charged captial gain tax in Australia as the property sold in profit. She plans to retire 2 sons from her trust now. She will keep capital gain in trust(not divide to her sons straight away to avoid tax) and buy another property for herself within a year in NZ.

Now, Mary asks me to be her trustee as she wants me to manage her trust. Such as signing documents, looking after accounts etc. I assume she wants me to be as a professional trustee whom have limit liabity to her trust. I am not sure whether or not I should be her trustee. I don't want to worry too much about her family issues. I don't want to be involved with something I don't know. I just one of her closer friends.

Would you please advise me what I should do?

Already Tried:
I told Mary that I will think about it. I want to help friends while I don't want to have trouble or headache later as Mary are nearly 65 years old. I assume she wants me to look after her as a mum if I can. Not sure.