P.B.
Hi A.,
Honestly, lying may not be the issue here, it's the deception and it sounds like it really hurts you. Sorry to hear that.
My 7yr old "makes up stories". For example, she told me that she and a girl at school are such good friends, the other girl is gonna invite her to her birthday party. I simply corrected: You and the girl are such good friends that you hope to go to her party, right? Then I explained to her to be careful about what we want and what is real. Your situation seems different because she's attempting to deceive you. Please understand though, this is a very confusing time for her. At 7, she knows both lying and stealing is wrong. But she feels she may be able to get what she wants by creating lucky accidents in her favour.
I had a 9yr old boy in my care who used to steal from my classroom and pretend he didn't. I helped him create a list of things in the class he'd like to have at home. When I confronted his parents I presented the list as an option for birthday and xmas gifts. She may need reassurance that you're making every effort to meet her "needs". Of course YOU ARE, but we never move fast enough for children! I'm not advocating for spoiling her, just letting her know you're seriously interested in some of the things she likes.
Also be careful how you phrase questions. I had a beautiful mentor (50yr master teacher) during my student teaching days. She always said never ask kids "Did you...?", ask why they did it. If you think about it, we already know they did it. All we want is to know why and to get an apology. Other phrase is almost a mind game that often backfires, allowing the child a chance to blame someone else or create false situations.
Good luck!