Hi Jillian,
Might sound crazy but what we used for both Willow & Jake (at night) when they first came home was a "Co-sleeper"....used for infants...you may even have one!

We didn't keep it attached to the bed but set it up next to the bed. We actually kept the pup in the lower zippered part (vented) with a tiny cat bed, blanket, pee pad, little bowl of water and kibble. That way one of us was right there if they cried. Even though we have stairs to the bed, they are too little at that age to climb them and we wanted them close by. If Alfie sleeps with you now, he will see that Evie has her own place to sleep, he won't feel "pushed aside"....and believe me, the time will come when Evie will let you know that she is a big girl too and the Co-sleeper will be put away...which reminds me...if you think you could use it, let me know.....