I have absolutely nothing against Spanish people or the language. However, some children seem a little confused, and therefore appear "speech-delayed", if they are taught more than one language at once. (While your caregiver may not be trying to do that officially, that is what could be happening for all intents and purposes.)
Perhaps a good idea, since this is a critical time for your DS language-wise, would be for you to ask your caregiver to speak only one language at a time to your DS until he is confident in his English skills. After he is more proficient in his English, then she can feel free to teach him Spanish if she wishes.
FTR, I have known bilingual Latino parents who have done the one-language-at-a-time thing with their own children when they are speech-delayed, so it shouldn't be offensive to ask in that way.
Children do, however, tend to develop one skill at a time. So, if your DS is currently concentrating on motor skills he may not be developing language skills as quickly right now. If that's the case, give him a few months before getting too worried.
HTH!