R.S.
First, you never need to stop rocking your child, who will still be comforted by that when she's 16 and you wrap your arms around her and rock standing up. But rocking her to sleep, while precious, gets tiring. If she goes back to sleep for daddy, then the thing is that she knows you're a sucker and daddy's no nonsense. Rock her early in the evening or during the day while reading a story or watching tv, so that she has mom cuddle time, but at bedtime if you're rocking her every night, start changing your routine. Rock her before bath time, then put her in bed and read a story or sing a lullabye while sitting next to her and patting her. Maybe daddy would put her to bed for a week or so while you break the rocking at bedtime habit. You don't want to lose that sweetness sooner than you have to, but this way she'll learn that she can go to sleep without rocking even when you're there, and she'll still get to rock sometimes. So reinforce the love and closeness while changing the bedtime habit, and it'll be faster to get her back to sleep.
The toddler bed is good timing because you can sit on the edge and tuck her in and read a story, and develope a new routine. Changing beds can go along with new Big Girl bedtime habits. But as the mom of teens, I want to stress that soon enough when you want to hug them they'll pull away, or allow it only for a minute, so get all your hugging and rocking time in now but earlier in the day!