Dislaimer: This answer is only relevant for full term healthy infants, in an uprght position that entirely follows T.I.C.K.S. guidelines. Any queries use the “contact us” page to speak to me!
Short answer: No.
Long answer: Nooooooo 😉
Science bit: Essentially the time limit on being in car seats (an hour and a half for anyone who has managed to miss that) comes from the fact that oxyen levels for babies can drop when they are in that sort of position so they need breaks. There aren’t those kind of problems with slings/carriers so there is no real reason (other than the times she would naturally be out the sling anyway) to suggest that there is anything wrong with protracted periods of babywearing. (Quick citation for lowered oxygen claim: http://pediatrics.aappublications.org/content/124/3/e396.abstract and http://www.whichcarseat.co.uk/the-medical-evidence-car-seats.cfm)
Anecdotal additional: Look at places where babywearing is the norm, babies are carried all day and are entirely fine.