We have savings in pounds and in dollars. How do we split them between monthly income and emergency money?

The simplest way is to treat each currency as a sum of its own. For each currency there are savings products in that same currency: savings accounts, deposits and certificates, at many banks, and returns are paid in the product's own currency. So if you want monthly income and emergency money, you can make one split in pounds and another in dollars, each with a liquid portion inside a savings account and a locked part paying monthly for a term you choose. Each part is priced at the amount it holds and currency, and minimums and available terms differ between the two currencies, so do not assume a dollar product works like a pound product. It also makes no sense to compare a pound rate with a dollar rate as if they measured the same thing, because the currency itself differs. Converting from one currency to another is your decision, and no one can tell you where the exchange rate will go. Ask the bank about the minimum, the terms and the payout schedules available in each currency, check them in the product's key-facts statement, and also who will hold the account or certificate.