It depends on the passport she holds. If she's on the list on visa-on-arrival countries then yes; if not, then no.
Taken from the (London) UAE Embassy:Passport holders of the countries listed below do not require a prior visa in order to enter the United Arab Emirates for business or tourist visits lasting 30 days. These passport holders will receive a one-month non-renewable visa on arrival.
Europe: France , Italy , Germany , the Netherlands , Belgium , Luxembourg , Switzerland , Austria , Sweden , Norway , Denmark , Portugal , Ireland, Greece, Finland , Malta , Spain , Monaco , Vatican , Iceland , Andorra , San Marino , Liechtenstein.
Other Countries: United States of America, Australia , New Zealand , Japan , Brunei , Singapore , Malaysia and Hong Kong .
If you do NOT fall into one of the above categories, you will require a visa and a sponsor for your visit. Please contact the Consulate Section for more information.