Wow, thanks everyone I started this thread then forgot about it. Didn’t expect so many responses, so thank you all 
Seems quite split really, with Connie coming out maybe slightly on top? Although most people preferring Constance with Connie as NN. I’m not sure how I feel about Constance, I don’t dislike it though.
I think because we have another daughter with a slightly old fashioned name, combined with Connie they might both sound a bit dated. Where as April sounds more fresh? But I do love Connie.
It’s a tough one!