Help identifying trio

Can somebody help identify this trio spotted on my bird feeder. The two on the left seemed to be the adults with the one on the right which is slightly darker possibly being a juvinile. The only reason I think this is the case is that it was having difficulty using the bird feeder and kept sliding down the branch whilst feeding. The other two have quite long legs and unlike most of the other garden birds had no trouble gripping the feeder and hanging upright and sideways to feed. They have long pointed beaks and a greyish brown plumage. Similar size to a blackbird but slimmer in the body. Not seen in the garden before.

Location Norfolk