A fledgling sparrow bird has flown into my house and is hiding under the armchair in the living room since this morning and does not want to leave. I don't want to scare her, but I'm also worried she'll die of hunger alone. I left the big window next to the armchair open and she could easily walk out in strides if she chose to, but she doesn't try at all. She doesn't look injured and she has also flown a few feet high inside the house before choosing to go down and hide under the armchair.
She then hid inside an old sheet in the living room for the night and she is still here today standing on a painting frame right next to the window but she doesn't want to get out...I don't want here to die of hunger...Its been more then 24 hours and I don't think she has eaten or drank anything in that time.
Someone maybe knows what to do in such a case to try to help her?

Thanks for any answer