Big girl underwear

I started having Mirin wear her big girl underwear (not all the time)tonight. She was quite excited to wear the Dora pantie. I didn't think she was ready to say bye bye to her diaper yet. But She did well when we were at home using either toilet or her potty for both number 1 and 2. She didn't wear diaper at home for quite sometimes now. I only put diaper on when we went out. I was a bit nervous not to put diaper on her when we left home because she still peed in her diaper and didn't ask to use the bathroom when we were out. Her teacher at school told me that she was ready for big girl underwear but I was so afraid of multiple accidents. Therefore, I started her on pull up instead. I thought in a few weeks I might let she go out without her diaper. May be she was ready but I was not.