ANSWER:

There is no sin on you for this if she abides by the proper hijab. You are not ordered to investigate or to spy on people’s lives like this! 

I was ordering jwelery online . So I asked a friend if she wants anything . I’ve seen her doing hijab , but I don’t know if she will do hijab in her home country in front of her cousins . If I bought the jwelery for her , and she does not do hijab , am I sinful ? I just ordered the jwelery, the money was hers .