not familiar with your country caseih but I have been to the big thicket and the part I saw was fairly flat but one heck of a thicket. It would be tough to bust a critter out of there and I am sure at least as tough if not tougher where you are. Up here everyones critters get out once in a while, if i see a neighbors animal i call him and vice versa, I doubt a person that has been in the business for a while has never lost a cow, some are just fence crawling, pains in the butt. As for some of these people thinking you do not know how many cattle ya have they didn't get the jist of your statement, I'm sure your numbers vary as does any herd due to culls from being open, grass conditions, hay supply, blah blah blah.... Not to tough to figure out. I don't care how many cubes ya put out the beef animal will mill around and jockey for position. and counting at the gate can be tough too. Up here we only run 20-25 pair to the quarter so when they are on grass it is easier. As for your problem, If you can guess weight fairly well, and if your vet will sell you some get a tranq. have him shoot it or yourself, hopefully near a place you can load, if not give her enough to knock her down, maybe hobble her, get a good horse and start dragging. It would be nice if she could still walk so you could kinda lead her to a pen , you must have a few panels around. Up here cattle getting out does not make you liable unless there is a history of your animals getting out. (Open range law) this is not open range country.