She doesn't want to bring her whole closet to Michigan with her, so I had a good time putting together an illustrative scenario that would allow her to only bring a carry-on bag:
Although she may need to wash/Febreze some clothes, it's possible to dress for varied occasions with the same pieces. At the barbeque, a great pair of dark slim-cut jeans will look casual but classy with a ruffled blouse. Then, the same blouse can be paired with black slacks (or a skirt) and blazer for work. A basic black dress can go casual or church-appropriate for Mother's Day depending on the jewelry and (optional) cardigan, then make a second appearance at work with a blazer on top and serious heels. Finally, some casual pieces that are perfect for the baseball game can be remixed with jeans and other layers for the plane ride home. Add some pajamas and 1-2 more shirts just in case, and you'll be set!