I have some information though probably just basics
1. Friedrich Eugen was a candidate for the Spanish throne but he refused it (Interesting, because her sister is a Miguelist Duchess of Braganza)
2. Luise was a fashionable woman and when she was a new bride, the empress altered her dress without Luise's knowledge or consent. Luise saw the dress was different when she was about to wear it. Luise asked her maid about the dress and the maid said it was the empress who altered it. Luise scolded her about not consulting her and ordered the maid to alter it back.
Luise then said to the empress that she had shown the dress to her mother and her mother approves it. The empress had to hold her tongue to that remark