offer to meet her without kids.
could still be very raw for her to see your ds.
she may....(just may) have suffered m/c or failed IVF or other options in these past 20 months you have had a LO and been pg.....
any of these things would make seeing you being horrendous for her.
give her space.
offer to meet without kids.
try writing her a letter if she wont meet.
if still no response give it up for a lost friend i'm afraid.
she may be very put out or jealous and doesn't like herself having these emotions around you and you LO's .... and is choosing to seperate herself as its causing her too much hurt and mixed feelings to see you.
you could.... .... ask her to be godmother if your planning on christening LO? if she's a very valued friend as you say then you would probably do this anyway.
only works though if your going to christen LO
might ease some of her feelings towards not being able to have anymore dc and help mend bridges between you two.
also.... not saying that you have... but is there the possibility you have got over excited and "gloated".....hmm... this isn't coming out right.
perhaps you have said things which have been a bit cutting for her to hear when you were excited about being pg and new LO arriving which she has taken as critism(sp?) or you having a dig at her?
even if you haven't.
when you do meet or write a letter.
it wouldn't do any harm to start off by apologising along lines of
"sorry, i've been pre-occupied with whats going on with me, and perhaps a little insensitive to talk so openly about it when you are ttc. would you like to talk about whats happening with you?"
meet somewhere without kids, and not in public incase the flood gates open.