In this situation, I would forgo the baby shower. No family in town, friends are all struggling, so who is there to invite to the shower?
I would instead take the money that you would spend on the shower and take her shopping at Goodwill, Salvation Army, garage sales and pick up some good, used clothes and other items. Spread the word through friends that you are looking for good, used baby items if anyone has anything to sell or give away. Buy diapers in bulk. She needs the essentials not the frills for this baby.
Help her find the resources available in your town that can help her with the baby.