These two artists are totally different in the way they sound and the only things they have in common are their first names and that I have recently downloaded their albums and love listening to them!
Laura Marling is more contempory folk and folk rock. I downloaded both her albums Alas I Cannot Swim and I Speak Because I Can, after listening to one of her songs on my friend's iPod at school. A few days after she won the BRIT award for Best Female Solo Artist and I was like woo, I actually know who she is! because she is not that well known. She's linked to Mumford and Sons because their style of music is similar and they have supported eachother at gigs. I love Mumford and Sons too! My favourite songs at the minute from her are Ghosts off her first album and New Romantic which is actually on neither of her albums.
Laura Jansen is more under the genre of indie pop. After downloading her song Single Girls which I saw on youtube, I decided to download her album Bells a couple of days ago. I love it. I think you can really relate to her songs and they sound so sweet - they're good when you want to relax! She has done a cover of the amazing King's of Leon - Use Somebody (is it me or does everyone do a cover on this song? :/ ) However unlike some of the covers I've heard, this is really good and in my opinion totally different from the original. Favourite songs of hers from her album: Single Girls, Use Somebody and Wicked World. Wicked World is actually great and quite humourous if you listen to the lyrics carefully.