A girl i like

This might be a bit complicated but bear with me. So theres a girl whos been a family friend for a while, she doesnt go to my school or hobbies so i dont see her that much although she only lives a 20 minute drive away. In person, shes really talkative, kind, caring, everything you want a gf to be. But when we're not actually talking in person, instead we're texting, she doesnt check her phone much at all and her replies are only a few words. Conversations just take so long because she doesnt use her phone much. Its really frustrating because when we're physically together she likes getting close to me and we talk and talk and hang out for hours, but when we text its almost like she's a completely different person? I know that she is single but has this ever happened to anyone? I suggested finding some time to hang out and go get some food together sometime and she seemed up for it, but its confusing!!

so what's the problem?

its like we cant develop our relationship when we're not physically with each other

have you just decided that's she's your gf or have you discussed this with her?