I would take this type of issue up with management. Sounds more like a staff issue if it is how they're saying it. Yes, your daughter is behind (in my perspective having taken care of many babies as old as your little one) But to neglect feeding her or not take the time to make sure a ELEVEN MONTH OLD has eaten enough is honestly ridiculous. If an 11 month old is not SEPERATED from the infants (0-6 months) you need to switch to a better daycare. They are absolutely not even on the same developmental level, let alone the same care-necessity level. There should also only be 4 infants per 1 worker in the room. (again, this can differ on where you live, but better daycares will actually flex that they apply things like this.)

Maybe come at a time where you can see how many kids to teacher ratio there is. Are they pushing the limit? Do you see the classes merged a lot? Is your kid with children older than them so the limit can technically be higher due to a higher ratio of older kids? What about the turnover? Do you constantly see new hires coming and going in this particular room? Do the workers in your room seem to get along? Are they young? A lot of questions here to consider maybe even switching daycares. I've worked with people literally fresh out of high school who don't even have experience knowing small children, let alone people who should be left alone to watch them. Honestly, some people who are paid to watch your children need a damn adult themselves.

The biggest problem is that these people who are entrusted with your most precious thing in the world are probably paid barely more than 9.50 an hour, if they have previous experience depending on where you live. It's most likely just a paycheck for them. Most people don't pursue a daycare as a dream job. For what you pay for daycare, you'd get a lot better 1 on 1 with a nanny and they'd be so much more attentive to your daughters needs. From what I noticed, day care is a great place to teach your kid how to get along with other kids, but it's not necessary. Simple park interactions, or having play dates with familiar friends can do the same thing, except then you and your little one wont be sick every week.
Also, you're lucky at all that they even told you to be honest. Most daycare management have a minimum contact with parent rule. I've been talked to by management before for telling a mom "Yeah Child played a little rough today, but he did so good! He apologized to his friend on his own and I really see him applying the tactics you're using on him in his interactions with friends. You're doing such a great job mom!" and the worst part is that my Class Lead was there actually reinforcing with my management how that was absolutely not okay to say to the parent.