I'd normally only suggest upgrading the body once you know what it is about the old one that's limiting you. If that makes sense! Spending more on a body will give you better autofocus - but has your's been a frustration so far? It's likely you may find it a bit slow and inflexible if you end up doing a lot of in-flight action shots, but for a bird on a branch? More than adequate. A newer sensor will give you a reduction in the noise at high ISO, but if you tend to only go out when it's bright & sunny that's not a problem either. Frames per second and the buffer depth is the other thing you'd get with a more expensive body, great if you like that machine-gun rattle & very useful for those action shots once again, but only you can say whether it's important to you at the moment (and remember, more shots, likely larger files, added together probably means extra storage required for the PC).
Finally (but maybe even more important) is the ergonomics. The larger bodies (eg 80D, 7D2) have more user controls immediately to hand (or thumb) and are generally faster to use once you get the hang of them. They're more customisable too, which can help tune the camera to your exact needs. However, you need to know and understand those needs before you can successfully start fiddling & there's a danger you can get in a muddle if you're not careful. They're also generally larger & heavier (which may or may not be an issue for you) due to their improved build quality (metal alloy frames etc under the plastic). Definitely handle them before buying to decide whether a particular body will suit you.
Had you experience anything frustrating to date with the camera you have?

Great advice Joe, thanks.

Nothing major that has frustrated me. I've been getting to grips with getting off of auto and feel I have an ok grasp of it now, but obviously I will be going out and taking more pictures. I think I probably just need to use it more to find out if there is anything that frustrates me so that I know if/what I need to upgrade to

You have just said it Lorri, getting off of auto is the best thing and thanks to Joe, you have a thread to look at, your camera can do what all the pro's can get its getting the feel of your equipment the camera is the tool the thing that lets it down is the lens, I have a cheep lens £1.800 and want a better one £5,000 but sadly I found a hole in my pocket and all the money was lost but will save up and get one in the end :)