DD is a bit the same...I think at around this age they tend to get a bit of separation anxiety, with DD it's also "any other person but mum' anxiety too...lol. She even hates going to DF sometimes and will cry and try to get away from him until she is back in my arms, or clinging onto my leg. Does she have any teeth coming through at the moment? Often that makes them worse.
Hope she improves a bit soon...does she like playing peek-a-boo? Maybe you could hide behind a door or something so she can't see you for just a few seconds but once you start playing then she'll know that you are still there and haven't gone too far away.