1 Crossed legs
As per the body language, people cross their legs because of various reasons and jealousy is one of them. If you talk about your or your kid's achievements and the other person instantly crossed their legs, this means that he is not happy about your success. They might do it unintentionally, but you would get to know their feelings for you.
2 Touching the nose
It is said that people usually touch their nose when as per them something is negative. When you talk about your awards and recognition, and you see that another person is touching their nose. This indeed depicts that they are jealous of it. (See Why do people touch their nose while speaking?)
3 Smaller body
When a person thinks that he is treated less important than others, in such cases, their body becomes smaller. You can notice it very quickly as they might fold their arms or shrink in the chair or sofa where they are sitting. They would take less space as compared to normal. This means that they are not happy seeing you or your achievements and so it might lead to jealousy.
4 Touching the ear
As per the body language, people touch their ear when they hear something negative. If you see a person reaching their ear as soon as you tell them anything good about yourself, be it achievements or promotions, then it implies that he is jealous of you.
5 Folding their arms
People fold their arms for numerous reasons and one of the reasons for it is not acceptable to what the other person is saying. When you see a person folding their arms after you tell them anything good about yourself, this means that they are jealous of you. (See Why do people fold their arms while communicating with others?)
6 Curved back
People curve their backs when they do not like something about themselves. If you tell someone about your accomplishments and success, and they bent their back this means that this news made them feel less worthy.
7 Big silent moment before compliments
This is something you might have experienced a lot of times. Jealous people do not get words to compliment you. Thus, they might take a big silent moment before congratulating you or saying any good words about it.
8 Shock and amazement
When a jealous person hears about any of your victory or attainments, they might go in a state of shock for a moment. You would be easily able to notice that the person is unhappy, low, and anxious after listening to your achievements.
9 They will want to leave
You would be able to see it on their face as they would become uneasy and feel like leaving the place as long as you are present. To end this pain and not to show that they are jealous, they would leave the site quickly.
10 Less frequent contact
As the person hears about you're your good news and feel jealous about it, they might stop looking at you and do very less eye contact with you. They do this to protect their ego as they do not want to show that they feel bad listening to it.