Wrong! Never delete numbers! You never know... what if you Freeze Out and she comes calling? Life is not predictable. Keep the number. Deleting it is an emotional beta move. It gains nothing. It doesn't hurt her. Its pointless.
And also... keep women friends around always. They can put in good words with other women ... sometimes even doing the work for you. Remember you are unaffected. You may not hang out with her all the time but its better to keep her as a contact... keep the lines of comm open.