Laundry for a Sephardi by an Ashkenazi starting on Rosh Chodesh Av

Is it permitted for an Ashkenazi woman to wash clothes for a Sephardic family during the Nine Days? And if she is already operating the washing machine, is it permitted for her to add a few more items of her own clothing?

Shalom!
It seems that there is no prohibition for an Ashkenazi to wash for a Sephardi, since there is no prohibition for the Sephardi, and the launderer only has an issue of 'Marit Ayin' (appearance of impropriety); but between Rosh Chodesh Av and the week in which Tisha B'Av falls, 'Marit Ayin' is not prohibited.
However, it is forbidden for an Ashkenazi to add his clothes to a washing machine that is operating for the benefit of another, even when it’s permitted to the other, or to a washing machine that is laundering little children's clothes.

Based on Shulchan Aruch, Orach Chaim, section 551, Mishnah Berurah, paragraph 43.