I guess I've been lucky in that my SBs have all been affectionate via text as well as irl.  We don't text frequently, that's part of the agreement, to NOT blowup each other's phones.  But when we do there's lot of "miss you daddy" , "luv u" and heart emojis.  It's nice and it's reassuring.  Maybe you could tal;k to her about it, see what she says.

When you are not together, she has her life.  She's not your girlfriend.  But when you are together she sets that time to be all about you and her.  Where you get to share that time and no one else matters.

If you want the communication between dates, tell her that.  And tell her if she wants the consistency she's already enjoying this will make you more likely to be with her long term.  She sounds like she wants stability which you provide.  Biweekly dates with an allowance.  Let it comfort her that you want it from her too and this is all she has to do to get it.