Answer:
Cannot say for sure which is ball 1 and ball 2 since the information on where the friends were was not specified but, one ball speed is 9 m/s and the other is 19 m/s.
Explanation:
Relative to the girl running at 5 m/s they were going 14 m/s but that could be that is was going 9 m/s towards her from the front so the combined speed is 14 m/s or that it is coming at her from behind at 19 m/s so the combined speed is once again 14 m/s.