Putting LO "down for the night" question

CA2006

DD is a little over 5 weeks.  I know that routines don't do much except help mommy and daddy keep their sanity at this point, but we try for EASY with DD. She will nurse to sleep still sometimes during the day and I let her, otherwise we'd deal with an overtired mess.  But nighttime is so hard.  She will wake from a "nap" around 5:30 or 6pm then either nurse back to sleep or have a little awake time.  She will wake to eat around 9 and that is what we have used as her "bedtime". But shes been consistently having a very alert period at this time, which makes bedtime hard.  She will wake to eat, so I feed her, then she will be totally awake.  We do PJ's, (bath if it's bath night), swaddle and rock to sleep.  But by the time she actually goes down, it's taken so long that we really only have 1-2 hours max before she's up to eat again.  She has never gone more than 3.5 hours at night without eating. She is EBF and gaining weight rapidly (over the normal 1 oz. per day).  Any suggestions on what we can do to help either get longer stretches or just have a more consistent routine?