Hair extensions for short hair

Hi,

I don't know if anyone can help me! I work more with beauty and nails and have no idea about hair related issues.

My mother has had cancer treatment - chemotherapy, mastectomy and radiotherapy. This ended around 6-7 months ago and her hair is growing back but very slowly. She is talking about having extensions on her hair (mainly on the fringe) but her hair is 1-1.5 inches long. I just wondered if this is long enough to have extensions and what type ?

Thank you