Fillyaw...Ashley County, AR

I have been unsuccessful in finding any information on Martha Fillyaw or her daughter, Amanda Fillyaw.Both are listed on the 1880 US Federal Census for Marie Saline, Ashley County, AR. Martha is listed as mother-in -law to Uriah McDonald (Amanda is his sister-in-law).Martha's was born abt 1830 in MS; Amanda born abt 1864 in LA.Amanda's sister is married to Uriah McDonald and she is listed as Mary J.H. Martin, born abt 1861 in LA. I have found a marriage record for Uriah to Mary for March 19, 1873, in Union County, AR, but have no other info on these Fillyaws.Would appreciate any help if you have info on this family.Thank you.