"Udde" = promontory, cape, ness
Ortsnamnsregistret have several promontories in different lakes in Piteå parish named Långudden.
There is also one farm named Långudden, but the text says that is a mistake, the farm actually belongs to Älvsby parish.http://preview.tinyurl.com/adgu9vghttp://www2.sofi.se/SOFIU/topo1951/_cdweb/phpform/nbt1.php?s...
Perhaps this farm is the Långudden where Brita Johanna Strand lived, or maybe she lived at some smaller place also named Långudden.
// Bo Johansson