Hi Kanishka,
She may have preferred that you talked to her and tried to get to know her earlier, before the Christmas holidays.
Being that you didn’t do this, there was no rapport established between the both of you. In essence, she doesn’t know you, at least not well enough.
She may not feel comfortable following someone on Instagram that she doesn’t know. This may also be why she didn’t accept your friend request on Snapchat.
You may have to talk to her in person when the Christmas holidays are over and work on building a rapport with her over time. This may be the only chance that you have to get her to consider you as someone with romantic potential.