Oh gosh, I'd forgotten about this post - I've spent the last few days
trying to get rid of a very stubborn trojan - grr!

Well, the animal behaviourist phoned back, and this is what she said:

It's not _very_ common, but not unheard of.  It's usually a comfort
thing - and not always to do with not being fully weaned (which she
was).  It could be the slight conflict between them and our older cat,
Macavity that's making her do it.  She suggested that to try and stop
her from doing it, when I spot it, I should pull her away and distract
her with a game.  She wasn't too keen on the water pistol idea because
it teaches them to fear you, not learn that what they're doing is wrong.
We do tend to use it though - but reserve it for when they're doing
something potentially dangerous.  However, she did say that ultimately
it was up to Ella to show Lou that it wasn't acceptable behaviour - it
is annoying her, so she thought that eventually Ella would bash her.

However, I haven't seen Lou try to do it for a while now, so it's
possible that they've sorted it out amongst themselves.  The two of them
are - as I type - cuddled up together on top of the fishtank, and it was
happening when they were both tired.

As a plus, my husband said that he saw Macavity washing Lou yesterday -
which is a very good sign that he's starting to accept them!  I'm really
pleased.  Macavity seems to be making excellent progress - slow and hard
work, but getting there I think.

And the two of them are wonderful - thank you for asking!  Still very
naughty and very boisterous - but soo affectionate!  It's impossible to
be cross with them when they're tearing about the place, knocking things
over and spreading paperwork all over the livingroom floor!!

How is your little one??