Below I’ve started with a copy of how the first card looked and then how I’ve changed it to finish it:
I didn’t change too much just adjusted some colours adding in some pink for the cheeks, and including a grey outline around the face and legs just to add some definition. I also changed the colour of the text to seem less accusatory/negative, the red looked more like a threat, so the purple/red is a bit more warming.
I also worked on the inside of the card, I wanted to keep it simple, but complete the idea started on the front. I think I achieved this by using the same banner and writing and completing the sentence. The little piece of pie in the corner is just a fun touch.
I think the text on the inside of the card helps the reader realize the card is celebrating the persons weight gain as an landmark in their life, rather than making fun of the person. It’s a thin line between being an insult and a compliment so I hope overall I’ve got it on the compliment side! I also think the banners help add some movement and colour as well as a visual link to the design on the front (which works well).