Simplify the following text for a Grade 9 native English-speaking person.
Original: Also in 1969 , Heather was formally adopted by Paul McCartney through legal process ( and with prior consent from See , her biological father ) and took the McCartney name .
Simplified: McCartney adopted Heather , who took his name , and Mary McCartney ( named for Paul 's own mother ) was born early in 1970 .