Hi, my daghter is 4.5 and has a severe spech disorder and some other issues which she is being asseced for. She dosn't seem to know what's appropriate with strangers and often says to them "I love you" or "I love you all the world". (they always look to me to translate). We went shopping yesterday and every person she met, she went right up to them and asked them there name, then chatted away to them. Not all of which I understood. She walked passed a Man in a shop and kissed his bum yesterday. Luckily he didn't notice. I told her that that was not very nice, and she said "It was kind and lovely thing to do." She used to be very shy, but has so much confidence now. I don't want to knock it. It just gets very wearing and sometimes embarassing for me though.
She sounds loving and confident, which is great, and you have years to teach her what is appropriate before she is mixing with strangers without supervision. My outgoing older dd has become more shy with strangers as she's got older - suspect that's the normal way.