So I am utterly fuming. I have just had a call from a friend of mine saying she had found my DD (She is 3 years old) wandering around at the park on her own with no adult in sight. After about 10 mins DD's nanny comes back with a coffee in her hand and when my friend questioned her she said she went to the cafe to get DD a drink as she was thirsty.
The coffee shop is the other side of the park and would have taken the nanny around 15 mins to walk there and back. Plenty of time for a child to get injured or get into some sort of danger. Hate to think what might have happened if my friend had not been there. The nanny has been great with DD up until this point and she has been a nanny for 15 years so I am genuinely shocked by this serious lack of judgement on her part. However, I don't think I can trust her now after this incident 
Is this grounds for dismissal or should I be giving her another chance? 