I think the plan is that they're done in 2020. There's always the chance some coach moves on or is fired after the season and a commitment looks elsewhere (like Doyle with Nebraska). I could see Iowa looking for another big since they don't have much depth there and Ollinger is done after this year.
As far as 2021,
@cyberhawk and
@jockos had a good list on
page 7. Allison Ediger (#51 on ESPN, #48 on Prospects Nation) is already committed to Iowa.
Sophie Hart from Minnesota (#43 on ESPN, #39 on Prospects Nation) and Sydney Affolter (#45 on Prospects Nation) from Illinois seem like higher end prospects with mutual interest. There was an article in the Star Tribune last week about how Hart is a high priority for Minnesota so it'll be interesting to see how that plays out. Affolter will be playing for All Iowa Attack this year. Grace Hall (#42 on Prospects Nation) just visited a few weeks ago. Greta Kampschroeder is ESPN's #12 ranked 2021 prospect from Naperville. She used to play on All Iowa Attack but I think she ultimately ends up at a more traditional power. Lastly, Jenna Johnson, the #2 or #3 prospect from Minnesota behind Hart, has visited Iowa a number of times.