any thoughts?

HI! This is my first time writing in though I've been reading and viewing this site frequently since March-I am 26 and my husband 28: we have a 4 year old and in March delivered a healthy baby girl-she just happens to have an extra 21st chrosome. We had no idea until she was born-and then even after she was born the Dr's couldn't decide wether to test her for trisomy 21 since the only sign she had was a slight look in her eyes (she was delivered face up, so the flattened facial profile wasn't a flag to them). Finally the tests came back and here we are today. Anyway, my question is regarding development-we are involved in PT/OT and early intervention, so far she is meeting all the "typical child" guidelines for development (she's 9 months old) she is also VERY vocal babbling all day "baba" "dada" we have also been blessed with a clean bill of health (everything has checked out so far). Has anyone else experienced this? We received her diagnosis but since then it's been very positive (of course we've had our ups and downs and tons of Dr appts to various specialists and we've had our dark days) Again, we are very thankful for all of the 'positives' that we're experiencing but am I wrong to keep my guard up (I am just afraid that our luck will end)????
I would love any input....
Camille's mom-Heatherhttp://www.network54.com/Realm/tmp/1165873190.JPG