Is bad or no !!! help please !!!?

im 5'11 17years old going to be 18 in 2 month and senior and im talking a sopthmore 5' 1/2 , 15years old very cute, is this good!!! im not going to use her im not like that ... and she tex me alot ... should i go for it??? , its been a weeek , how long should i wate to ask her out !!!