How often do you think couples should text eachother?

Me and her are 15. I constantly see other couples texting their other when theyre not together. I text her maybe twice a day to start a conversation which usually lasts a couple hours.she doesnt always sound like she wants to talk. so sometimes i wait for her to text me But i know deep down she loves me and i dont doubt that. But the thing is, I ALWAYS have to start the conversation. she NEVER texts me first. I dont know, I feel like shes closer with her friends and coach/teacher (she loves her coach and our music teacher, not romantically, but i think she looks to them as father figures, she didnt have a good one growing up.) Is it weird for me to feel like she isnt talking to me enough? she tells her friends, then facebook, then maybe shell text me. I feel like the thought of me never goes through her head. Thoughts?