Is it normal to feel like your best friend is really jealous of you

One upon a time and my best friend were really close. But I noticed the closer we become the more she tried to put me down or make me seem stupid. Recently we began working at the same place and a few months ago on my way to class my purse was stolen out of my car on my way to work. Frantically I called her my best friend and the following day when I returned to work the whole job knew my business how it happened and everything I was so pissed. Then she wanted to have the audacity to laugh about it. Another incident was when she told my boss that I had three kids because she swore up and down that I was going to get fired and that was going to save my job. So I asked my boss about this incident and said he never was attempting to fire me just inquired about where I was? Then it's like at the time I was working there full time 10 hrs a day 5 to 6 days a week while also going to school full-time for fashion design in which I am going into my 3rd year to get my Bachelors of Fine Arts hoping to go to New York or California after I receive my degree and her and her sister would try to make it seem like I had nothing on in my life. On the other hand neither of them ever went to college and had been working at this job for 3 yrs like this was all they knew. Mind u guys this was a seasonal temp job which only lasted a few months. And by the way her sister thought of spreading the rumor I had 3 kids which I don't I have too much going for myself to have kids right now, but she does have a baby and her and the father live with her mother. Not to be catty just want u guys to better understand things. After we graduated from high school me and her kinda rarely talked and before we began to work together I forgot why? But I noticed she seemed jealous of me. Just by her attitude towards me and the childish things she did. She I stop talking to her? Give me some insight?