While I would appreciate a little more context, I think this is fine. It’s really saying “…when you can” rather than assuming the recipient has the same priorities and timeline.
If it were a real emergency, my mom would call. The rarity of her calls shows how urgent they are.
@levisan Texting to ask for a voice call seems perfectly normal to me. it could be non-urgent and still the caller doesn't want to explain things via text.
