It is definitely not a bad account, especially since you also have characters no longer obtainable and two nice healers. To help you a bit further in the decision:

-Nanaly is a black, aka very rare, but you CAN get her again.

-Belinda WILL be available again at some point if you are a completitionist, since they will do revival events at some point. This might be quite far from now though.

-Leveling your new account at the moment might mean you will have a very hard time with the next event that is coming, which means you might miss out on Odette, which is a real shame in all honesty.

I'd probably somewhat recommend something similar to Kotono - Play both accounts for a week or two and see how your new one ends up. If you get some more crystals and those summons are decently lucky, your new account will definitely outshine your old. If you can get your new account up in time to do well in the Odette event (aka manage to farm the last map) it will probably be the go-to choice.