this thread was from a while ago when Gill did a special Q&A for us. I don't know if she's dropping in now and then, but suspect she's very busy with her new book, so would you like some of us to share thoughts on your question?
I'd say that the most likely cause I can think of for frustration and tears would be tiredness at meal times. If you started BLW early because LO was grabbing from your won plates then I'm guessing you have a meal time at your own normal evening meal? This might be a bit late in her day to be able to cope well with the BLW. The other thing to bear in mind is making sure that she's not hungry. I know it sounds silly when you're giving her a 'meal', but we don't expect them to actually eat much if anything at such a very early age, particularly as you've started before 6 months. The best time to experiment with food is about 1 hour after a milk feed.
Remember that even if she has the skills to handle the food, her manipulation of it in her mouth might take a little while longer to get good at, so it will be a slow process. Keep things simple for her, keep offering plenty of milk, and come back and let us know how it goes!
If you really want Gill's personal advice you can always try emailing her (address via her website http://rapleyweaning.com