Birth Parents with Low IQ and Learning Needs

Hi all, My partner and I have been presented with a potential match, a seven month old baby girl. We are really excited about the possibility of the match, but also have some concerns that we are working through. Our main worry is that both birth parents have very low IQs (in the mid 60s). The baby also has one half sibling in primary school who has learning needs and according to the social worker is currently 'performing below average'. I have read a lot about the influence of both genes and environment on a child's IQ, and am just trying to work out how much influence we will be able to have on helping this child reach their full potential. We are also wondering what their full potential may be limited to, and how their potential learning disabilities may affect both their life and ours. We do not have particularly rigid ideas about what we would hope for a child to achieve as such, we would just want them to be as healthy and happy as possible. However we would really hope to be able to raise a child to live independently if possible. We are trying to be realistic about how the future may look for this child and whether we are the right match for them. Any insights or comments from those with similar experience would be much appreciated. Thanks so much.