It is hard to define ladylikeness because every person has different opinion. Also, it depends in what country you live, because every country has different culture, beliefs, and special ways of thinking.
In my opinion, being ladylike is behaving properly. For example, your friend has decided to take you out for lunch at posh restaurant in the city. Your attire is proper- no holes, just your size, smells fresh and no stains. You chew with your mouth closed, giggle at all his/her jokes, look into his/her eyes when talking. While eating, you fee the sudden urge to sneeze and blow your nose. You quickly grab a hanky from your handbag and sneeze into it, in a very dainty manner. You then excuse yourself to go to the bathroom if there is for it. You thank your friend afterwards for a wonderful time.
You are in the store, at cash register, standing in long line waiting to pay for your groceries.
There is this woman standing behind you and she is not happy because she only has few things in her cart and your cart is full of groceries. She is standing and mumbling something to herself and you get so mad that you want to punch her in her face. However, you swallow all your madness, smile and you say to her, "Would you like to go in front of me, since you have only few things in your cart." She continues to mumble something to herself, goes to the front of you not even saying thank you. While pushing her self to the front she drops her wallet and you pick it up for her because she is overweight and it is hard for her to bend.
Sometimes it is very difficult to behave properly "ladylike" especially when...