Why did she tell me her age?

The number is the least informative part of the message. What tells you something is how she framed it. A woman who says her age and then asks what you are into is signalling she wants to move past the topic. A woman who says her age and adds a qualifier, like 'I know that's probably too old for you' or 'don't be scared off', is telling you she has been judged for it before and is pre-empting that. Both are fine to answer, but they need different handling. Look at whether she is asking for reassurance or just giving you information. If she is asking, answer the implied question. If she is giving information, match her energy and keep it light. Also check whether she asked your age in return. If she did, she is probably sizing up whether you are on the same page, and a clean answer back will go a long way.

There are roughly three kinds of reply that fit this moment. The first is a plain acknowledgement: you take the number in stride, say something short, and let it sit. Its job is to show the age does not register as a problem. You can tell a draft is this kind when it is one or two sentences and contains no question about the age itself. It should leave out any comment about how she looks or how old she seems. The second is a redirect: you acknowledge the number briefly and then move to a topic she brought up or a shared interest. Its job is to get the conversation back to something fun. Good drafts here contain a question about her life, not about her history. Leave out anything that circles back to the age. The third is a light check-in: you acknowledge, then ask a low-stakes question about what she is looking for, which lets her steer. This shape suits a woman who seems to want to be clear about intentions. Leave out pressure or any sense that you are trying to close the gap she just opened.

Reply in the same window she used, unless it is the middle of the night, in which case wait until morning so the message does not read as eager. If she goes quiet after your reply, give it a full day before sending anything. One short follow-up is fine, something about the thing you were discussing, not a repeat of the age topic. If that gets no response, let it go. A woman who volunteers her age and then disappears has usually decided the conversation is not worth continuing, and pushing will only confirm that. If she does reply but the chat stays flat for several exchanges, ask once whether she wants to meet up, and if she gives a vague answer, take it as a no and stop.