Your mother-in-law Walburga was already controlling, when she learned that you were having a baby, she started to interfere with your pregnancy telling you what to do with the baby, for example that you should breastfeed and not use muggle formula, but you always told her that she doesn't choose what you do with your baby.

Eventually she decided to throw a baby shower you and Sirius told her you wanted a maroon and gold (Gryffindor theme) themed baby shower, since you would want to reveal the baby