My favorites are Lottie-Elise and Lottie-Amelia! I think that the sounds of [name_f]Lottie[/name_f] and [name_f]Isabel[/name_f] run into one another and [name_f]Faith[/name_f] isn’t my favorite personally.
some suggestions:
Lottie-Mae
Lottie-Claire
Lottie-Sophia
Lottie-Jane
Lottie-Leanne
Lottie-Louella (nicknamed Lottie-Lou? 
)
Lottie-Bea
Lottie-Wynn
Lottie-Hope
Lottie-Rain
hope this helps!!