Hi Sandra, I would go slow with her. Give her time to get used to her new surroundings, and routine. She is adjusting and she has likely been through some scary things recently. Let her get used to feeling the love and comfort in her foster home. It's possible she has never seen stairs before.
Once she is more adjusted to her foster home, encourage her follow you. Take a step and then she'll want to take a step. Maybe start with something easier for her. Like following you around something she is already familiar with, say a chair for instance. Walk around the chair and let her follow you. Praise her. Make her feel good about it. You could bribe her with a small treat. Then when you start with the stairs she'll have a better idea of what you are asking her to do.
#General