From the mother of an adopted 2-year-old girl:

Our daughter who turned 2 years old at the end of June arrived in Aug this year.  She had no attachment problems and bonded instantly.  She is the happiest and friendliest child I know.  We had more problems with our 4  year old daughter upon her arrival.  I was fearing all these issues for my 2 year old when in fact it was the 4 year old that had the problem of being the queen and now there is this new child in the house.  Since then
it has calmed down and the girls are getting along great.  I would opt for toddler adoption rather than be referred a 2 month old with the possibilities of having something turn up later down the line with a younger referral.