Unfortunately, scleroderma is not easily diagnosed. And, more often than not it is overlooked in it's early stages. The diagnostic process may require consultation with rheumatologists (arthritis specialists), and/or dermatologists (skin specialists) and require various blood tests, a process that could take months.
Is she does indeed have scleroderma, keep in mind that she would be very your for symptoms to appear. In some instances, localized scleroderma, which most often effects the extremities, primarily the hands, can be readily treated with a combination of drugs and some minor lifestyle changes, such as wearing gloves and keeping the arms covered to protect them from sunlight damage.
Most major medical centers have physicians that specialize in scleroderma, but you will have to get a referral from your primary doctor in order to see them. This would be an important first step in the process.