The name "auntie" is not commonly used in Guangdong, although it may be a common way to address older women in other places. If you call older women "aunts", it is not impolite, but some people may feel a little embarrassed or misunderstand your intentions. Therefore, in Guangdong, I suggest that you use a more appropriate title like "grandma" or "mother-in-law".
When dealing with older women, please be sure to treat each other with courtesy and respect, and show the values of filial piety emphasized by China traditional culture. Keeping good communication with them, understanding and respecting their habits and preferences will win their love and recognition.
I hope my answer can help you! Wish you all the best! (? )