Some good websites for finding memorial poems that honor lost loves ones are Elegant Memorials, Funeral Helper and Family Friend Poems. Most of these poems are completely free to use for any obituary because they have public domain licenses.
Elegant Memorials has several categories of memorial poems to choose from. The website has memorial poems sorted by type of family relationship, including poems for deceased mothers, fathers and children. There is a section for non-religious funeral poems and a section for "in loving memory" poems. The poems provided are mainly by unknown authors, but there are also poems by well-known poets like Emily Dickinson.
Family Friend Poems is a website for poetry in general, but it has a section for death poems and an extensive collection of subsections containing memorial poems. These subsections sort the roughly 700 poems by factors like type of death and the poem's intent. There are sections for a wide range of deceased family members, including brothers, sisters, uncles, aunts and lovers. These poems are written by users of the website.
Funeral Helper has a listing of anonymously written memorial verses in the website's "Bereavement/In Memoriam" section. These poems are all very short, ranging from two to 11 lines.