She may never text you first because she is bored with the kind of texts that you send her.
Hence, she may not feel inspired to initiate texts to you because she worries that she will not enjoy the conversation.
Try sending her a different kind of text.
Perhaps one that asks her a question about something that you know that she is interested in but has never gone into great detail about in your previous text conversations.
If she responds positively to this kind of text, she may feel compelled to initiate a text to you the next time around.