It does sound like you have a great sex life with your partner. Congratulations!
Female ejaculation is one of those areas that we still don't know a lot
about. There is even still debate about where this fluid is coming
from, although recent research shows it is probably the Skene's glands.
Whether women can learn to ejaculate is a matter of much debate. Although
there are a number of books and videos that claim to be able to teach
you how, it does appear that some women simply cannot ejaculate.
What many women report is that they are most likely to ejaculate with
sustained G-Spot stimulation.
While I understand that this is something that the two of you want to
happen, the best approach to take is to simply do whatever feels the best
to both of you. If you ejaculate, great. If not, but still enjoy yourself,
that is okay too. What is important is that you two have a good time together!