Needing advice on helping 5 yr old daughter cope with father not being around..

Due to both physical and mental abuse Ive moved away from the city my daughters father lives, he was constantly walking in and out of our lives, mentally unstable and coming off drugs whenever he would come back home only to leave and get back on it all, again and again.. The city i chose to move to was where my best friend lives. since we've been here in such a positive environment I've noticed how much she is thriving and is so confident, i can get through to her in so many ways, but she says she misses him nearly every night and sometimes cries, its been 8-9 months since she's seen him, sometimes she brings up recent events but brings him into it like he was there.. i don't know what to say... have looked into all the legal stuff, just needing some advice on how to help her get through and what do i say, how do i respond? :( if anyone has any advice or similar circumstance would love to hear what helped...