Being "with her" and "playing" are two different things. Some rabbits don't seem to need much actual "play" or one-on-one interaction. (Though your rabbit sounds like a sweetie following you!)
Since she is free roam, exercise time isn't really an issue. For rabbits that spend most of their time in a cage, 3 hours is usually a minimum because they seldom exercise on our schedule. That means that if bunny isn't in the mood to exercise during the hour his cage door is open, he'll end up with zero exercise. Hence the suggestion for 3 hours. (All of which is irrelevant in your case
)
The nice thing about rabbits is that you are spending "together time" if you are simply in proximity of bunny. For example, as I'm typing this, I'm just a few feet away from my bunny who is lounging in his open cage. In his eyes, we are hanging out together (since we're close [proximity] to each other). So we
are spending together time even if it isn't face to face interaction.
If you're concerned about her while you are away, Popsicles has some good suggestions for activities. You can also set up cardboard boxes with doors cutout for exploring and climbing. Changing toys and activities regularly can keep that interest level up.
You could also spend more time on the floor when you are home (whether reading, or on computer, or watching tv). That way she'll have more opportunity to be close with you even if you aren't giving her your full attention.