I don't believe she is entitled to any part of your pension, now if she had been your wife whilst you were serving then yes and then only a percentage depending on how many years you were together whilst serving.
A masterly summary! I am no expert on this area, but there is no doubt that pension entitlements of either or both parties are taken into account. The logic is that one spouse may have a much higher pension entitlement, and the other one would have had a reasonable expectation of in sharing in the general family benefit of that pension and perhaps eventually a widow's/widower's pension from that fund. As Scabster_Mooch hints, this doesnt necessarily mean the pension will simply be divided 50-50 between the parties; the pension and any house are often treated differently in the divorce settlement.
IIRC, everything is up for grabs regardless when you earned it.
Scabster_Mooch is not technically right by saying it is all up for grabs. However you do have to defend you right to retain the pension. Unfortunately that is why you have to get a good solicitor. While it is easy to show your current contributions you need to value all the assets she has. It gets to be like a set of scales which is offset in her favour because she has the children. There is also an element of showing that you earned the entire pension before you became involved and she had every chance of earning her own. That is to say she did not give up everything to support you and was therefore unable to earn for herself. However the court might count the pension purely as financial income that you have, so not the pension in itself but you have x amount of pounds per month. If you have a high value house, she might get it because she has the children but, a hold can be put on it. When the children are old enough to leave home it is then sold and you could possible get money back.
Get a good solicitor if you want to save money in the long run.