What you're doing seems to be working.
Is there some reason to believe R doesn't know you're thinking of her and that you miss her? Has she expressed feeling neglected? Or are you just looking for solutions to problems that don't actually exist?
The fact that you're thinking about this means you're probably already doing plenty to reassure her. Assuming she hasn't expressed that her needs aren't being met, just keep doing what you're doing.
Gralson: my husband (works out of town).
Auto: my girlfriend (lives with her husband Zoffee).
The most dangerous phrase in the English language is "we've always done it this way."