white ink on black tattoo cover up?newbie need advice

I just got my first tattoo and I'm not happy with my black ink angel wings and would like to soften them up, the wings themselves are pretty "bad ass" looking and it doesn't fit the theme. A little too rough edged when I should've gotten sweeter,smoother looking wings (probably screwed on shape chage too, right??) The tattoo is of my daughter's favorite and first rattle with her name going across it with the angel's wings on either side. I understand it needs to heal first, but how long should I wait? Do you think it's possible to cover up the black ink wings with white and some pink to baby girl it up? What colors can I play with to make is look decent? Thank you SO MUCH for any advice you have! This tattoo means a lot to me