There is hope! Has your DD been evaluated by a developmental pediatrician? If not, I highly recommend it. You need a global evaluation to help better understand what's going on. My youngest DS had very, very few words at age two - less than 10 and even those weren't intelligible to most people. His hearing was fine but but he didn't seem to understand directions. After 6 months of therapy, he still didn't have any carrier phrases (such as "I want..."). At the recommendation of his SLP, we started teaching him sign language which he had better success with. When he was 2.5, ASD was definitively ruled out by the developmental pediatrician and an NIH research team. It's easy to see why some might consider him autistic but now that he's older and we're seeing the result of the interventions we can see his lack of response and social challenges are primarily due to his communication challenges and executive functioning deficits - not to mention the developmental delays. Even though he's 5 now, in many areas he functions more like a 3.5 - 4 yo.
Does your DD have any motor planning/coordination challenges? The reason I ask is that it wasn't until my DS started working with a PROMPT certified SLP that we really saw improvement in his language communication. I found out about PROMPT through DCUMs, did some research on it and discussed it with our dev ped. It seems to be the therapy of choice for kids with motor planning/coordination challenges and I can see why. We've been doing it for a year now and I wish I had done it earlier. DS is still delayed but we've really seen heartening improvement, especially when we look at where he was when he came in.
One of the other things I think made a big difference is that he when he transitioned out of Infant Toddler (we're in Fairfax County), he qualified for a FCPS non-categorical special ed preschool. At first I was concerned about the functioning level of the other kids, behaviors he may pick up, etc (yes, all that ignorant stuff) but it was amazing. I'm so impressed with the it and it was an excellent environment. Since your DD is 2.5, you should start planning the transition from Early Intervention to Child Find. My DS started the special ed preschool before his 3rd birthday. It was hard on us at first (can you imagine putting your baby girl on a bus? or missing that afternoon nap?) but we all adapted and it was the best thing for him. You might also consider participating in one of the NIH studies. I've got three kids and between them, we've participated in a good number of them. The researchers are amazing, our kids really enjoyed participating, the researchers have been fabulous resources for us even after the study is over and the NIH reports are the best we've received - all at no cost to us! We've learned so much from them. I think this is the ASD study we participated in. You don't have to have a diagnosis and it's open to kids with 'developmental delays'
http://clinicalstudies.info.nih.gov/cgi/wais/bold032001.pl?A_06-M-0102.html@autism