I really love my teacher as a mother but i think i'm burdening her. he

We've had a normal student teacher relationship last year but ever since this year I realized that she is more than just a teacher to me. I really admire her personality because she is just a very happy and upbeat person. Ever since the beginning of the school year I've been emailing her consistently about 2-3 times a week about school stuff. I really try to be like a son to her and I talk to her and am very playful with her which I think she likes. I even bought her coffee one morning and she said I was sweet and she hugged me. But recently I feel like her emails are just short answers rather than replies with emotion or stuff. I'm getting really sad because of that. Here's the most recent email :
Me : "Guess what DAY IT IS? :DD" 
Her : "I don't know." 
Me : "my Birthday!! :)" 
Her : "Happy Birthday [Confetti emoji] [hand clapping emoji]"

I'm a 10th grade boy and she is 37 I think.