Simplify the following text for a Grade 11 native English-speaking person.
Original: Skirts had been getting shorter since about 1958 â `` a development Mary Quant considered to be practical and liberating , allowing women the ability to run for a bus .
Simplified: Skirts had been getting shorter since about 1958 â `` a development Mary Quant thought was practical and liberating , allowing women to run for a bus .