Another option -- depending on if you will be replying in email, in detail -- is to thank her happily for the information in the email, respond to that as appropriate, and just not mention anything about the apology one way or the other. In a face-to-face conversation, you could say, "It's all right" to an apology or some other small-talk, but making a point to address the "sorry I'm late" in an email would generally need to be done with humor or other truthful understanding about busy lives. E.g., after an ice storm, I was able to write things like, "No worries; turned out I lost Internet for three days anyway!"
(But if you do acknowledge the apology instead of just letting it pass off and indicating your no-hard-feelings by how you react in the rest of the message, another possible reply would be, "I understand; life gets busy. Thanks for getting this to me!")