Not too long ago, it was rare to find 20-year terms. In fact, an annual renewable term was one option, but your rates are almost guaranteed to rise along with your age. Many insurance companies now offer policies with 30-year terms, and if you can get one of those, it's usually worth your while. The likelihood of her health staying exactly as it is today is not all that good. Even then, you'll pay handsomely.
Life insurance is a gamble.
You're betting that you'll die before the policy runs out, and the insurance company is betting you won't. The table below shows how life insurance costs play out over age groups in rates from several companies. You can also view this information as a graph. It does pay to be healthy. Each company has its own underwriting standards and therefore may put you in a different risk class.