Older one is already 3 so she/he can go to k1. I will hire a maid with nb experience and tell her she may need to take care of 2 kids, possibly letting the old one go once she has proven she is ok.
I think one capable maid can take care of 2 kids if they are 2 years apart. Just don't expect her to finish all the housework when bb is young. keep one eye closed if she is nice to bb.