Hi G.! I agree, feeding her every 1.5 - 2 hours or so at night is not unheard of for a 14 week old. They are just getting on a schedule at that age. I found that by four months or so, both my girls were so much more predictable. It also sounds like she could be, or was, colicky. My youngest was colicky from about 3 weeks until 4.5 months (she was going for the extended version, as everyone told me it would end at 3 months and it did not!!). If you find that nothing helps, not feeding, rocking, swinging, etc., she could be colicky, in which case, you have to get creative. We tried everything, and in the end, a combination of gripe water (found at Whole Foods, which also has a ton of other great stuff, all natural remedies for babies) and the chiropractor worked, believe it or not!! Her digestive system was not working effeciently, which led to the colic, because she was backed up by the end of each day. My daughter was born by c-section and she swallowed a lot of fluid on the way out and had to be intubated, so it made sense to me! Anyway, it sounds crazy but the adjustments really helped.
Good luck - it will pass soon, I can tell you from experience! It's always a tough time of day at 5 p.m., no matter how old they get. :)