Whats the mean of a erfly landing on your heart?

The other night while my mum was at work she had a strange experience happen. she works with food and while frying up some hot chips she had a colourful erfly come and land on her heart. She said it was very strange as it was night time and in such a hot area and being so busy. Her mother ped away last year and she believes that it was something symbolic of her it was also the night before mothers day. Does anyone know the meaning of this or have anything similar happen to them????