Meghan Markle is supporting teenage girls struggling in the aftermath of the deadly LA fires.On Monday, the Duchess of Sussex, 43, dropped off donations and volunteered at a relief center in Altadena, Calif., run by Altadena Girls, a grassroots organization founded by an 8th-grade girl whose school burned down in the Eaton Fire.The young girl, Avery, has rallied locals to provide items such as clothes, hair and beauty products to her fellow teens who have lost everything in the blazes and are working to rebuild their self-confidence.Meghan’s visit was discovered after eagle-eyed Sussex stans spotted her in a video Altadena Girls posted Wednesday on Instagram showing people giving and organizing donations.In one portion of the montage, Meghan is seen arriving outside the center carrying large overflowing bags of donations and talking with someone who appears to be helping control the influx of items.The duchess struck a low profile, wearing a black tee, a camel-colored sweater tied around her shoulders and a black “LA” baseball cap.“And thank you to everyone who showed up on Monday, which was such a special day! We love you!” the group captioned the video.Meghan’s fans effused in the comments.“I can support my princess being her kind self,” one person wrote.“This is just amazing and seeing the community come together will only strengthen the city,” another said, while someone else replied, “LA filled with so much love.”A source told The Post that Meghan’s donations were provided through her and Prince Harry’s charitable Archewell Foundation, named for their son Prince Archie, 5.The LA native arrived with new clothing and beauty products, the insider shared, adding that she stuck around to volunteer her time and brought lunch for her fellow volunteers.Meghan also helped teen fire victims as they looked through the donations, sharing conversations with the young girls and providing overall support.Altadena Girls’ mission statement, as de...