Siblings and sleep solutions

Am too tired to write in full but have the challenge of living in a bungalow and not even having a basement and my toddler and my baby sleeping inches apart. The baby stirs every 20, 40 or 90 minutes throughout the night and the mommy pacifier is the only thing that quietens her and sometimes she also needs to be held or just wont sleep!

would love solutions from families with siblings and how they deal with sleep training the baby and not waking the toddler!

I am wiped!