Simplify the following text for a Grade 7 native English-speaking person.
Original: When `` James III '' was asked to leave France as part of the Treaty of Utrecht , Mary stayed , despite having no family there , Princess Louise Mary having died of smallpox .
Simplified: Later , `` James III '' was forced to leave France because of the Treaty of Utrecht . This left Mary without any family in France ( Princess Louise Mary had died of smallpox ) .