The apparent duplication of UK channels on your LG TV is because of the different BBC and ITV regions and the regionalisation (for advertising purposes) of Ch4. You will need to go through the lot finding the channels that pertain to your area and write down the related number. You will also need to do the same with the non-regional channels such as Drama, 5USA, Yesterday, and many others and put those down on your list as well. Then tabulate the lot by station name so that SWMBO can 'dial-up' the station she wants to watch.
Just to add some more into the mix, there are also a number of Sky FTA (Free-to-Air) channels such as the various news channels like CNN, France24, CCTV (China) etc, and the so-called 'God' channels if you want them. Occasionally Sky 'opens' some of their chargeable channels to make major events watchable in the UK which the BBC and ITV are not covering.
Frankly its a nightmare. It is simpler to get a Freesat box which are inexpensive, or there is a cheaper way. Troll along to you local Cash Converters and buy a second-room Sky box. These are very similar to the Sky+HD box but are much smaller as they have no recording capability. CC will probably sell you one with remote, mains lead, and guarantee for well less than £20. With luck it will have an expired viewing card in it which will place the channels for your area (specifically BBC1 and ITV1) in the right number slots (101 and 103 respectively.) If there is no card you can get a card from Freesat-from-Sky which will cost you a once-off £25. Freesat from Sky carries many more channels than Freesat and many of them are in HD. If you do go down this route be aware that as the box will not have been used for some time you may find that some stations are not available when you first use it - commonly ch4 and Five for example. All you need to do is leave the box switched on for 2-3 days and they will appear and remain.
This may sound a daft query, but why doesn't OH just use the TV on normal Freeview terrestrial channels. All you need do is plug in an aerial.
Oh, and one other point. Depending which version of LG TV you have it might be so-called HD Ready which means its resolution will be only 720p. If it is nominated as Full HD and has a green tick somewhere on the frame then it will be 1080p. Curry's were/are so-and-sos for doing this. If the TV is 32" or less it has a much greater chance of being only 720p. In optical terms, HD Ready will be 1366x768 pixels which is roughly 1 megapixel: a Full HD is 1920x1080 which is roughly 2 megapixels.