I recently helped out with a baby shower and it was all things Poppy, here are some ideas....
Poppy paper flower centerpiece (made with a Silouhette America poppy and pregnant lady)
Paper poppy and onesie garland (also made with Silouhette America designs)
"Thanks for Popping by", popcorn in a poppy bag, thank you treats
Plus some Poppy themed food such as a fruit and nut filled garden salad with poppy seed dressing.
Other ideas are that the soon-to be-mother is "ready to pop".
Other food we had: Sloppy Joe sliders (rolls and sloppy joe filling in a crockpot), Strawberries and poundcake (pound cake, sliced strawberries that had been mixed with a Tbsp white sugar to make juicy, and some whipped cream), a regular garden salad, and Rice Krispie Treats with red and pink M&M's to match the poppy colors--these were a major hit!!