Hi and welcome to Just Answer!
Your mother may gift shares to you - your basis will be either her cost basis or fair market value of shares at the time of gifting - whatever is less. If you will be forced to sell shares at a loss - that will be your capital loss.
Alternatively – shares may be transferred to the trust – but for the sale to be detached from your mother’s taxes – that should be irrevocable trust – so you need to consider overhead costs for maintaining the trust. Capital losses could be used to offset other gains or distributed to beneficiaries.