I can't see them either on Castle Garden on any ship but you know I'd bet a sum of money they were on the Adriatic since that is the name given to Hugh's sister. Do you have any idea what the initials A. O. stood for in her name? You don't happen to know a more exact date of birth for her? The Adriatic was on a regular run to NY during this time frame. All the voyages between 1887 and 1889 are found microfilmed as follow below but I think Castle Garden has all of them indexed online. Were there any Lester family members in the US or Iowa when they arrived? Oddly enough there is an arrival of a Miss A.O. Lester age 20 in about 1887 who was a US citizen. The early passenger lists unfortunately don't give final destinations.
1 M237 503 54 1887 January 17 305 Adriatic Liverpool, England 1027371
2 M237 503 ? 1887 February 14 718 Adriatic ? 1027371
3 M237 504 258 1887 March 12 413 Adriatic Liverpool, England and Queenstown, England 1027372
4 M237 505 376 1887 April 9 459 Adriatic Liverpool, England and Queenstown, England 1027373
5 M237 506 522 1887 May 7 472 Adriatic Liverpool, England and Queenstown, England 1027374
6 M237 507 670 1887 June 4 903 Adriatic Liverpool, England and Queenstown, England 1027375
7 M237 509 823 1887 July 2 115 Adriatic Liverpool, England and Queenstown, England 1027377
8 M237 509 949 1887 July 30 941 Adriatic Liverpool, England and Queenstown, England 1027377
9 M237 510 1085 1887 August 27 893 Adriatic Liverpool, England and Queenstown, England 1027378
10 M237 512 1230 1887 September 23 174 Adriatic Liverpool, England and Queenstown, England 1027380
11 M237 513 1364 1887 October 21 425 Adriatic Liverpool, England and Queenstown, England 1027381
12 M237 514 1487 1887 November 19 278 Adriatic Liverpool, England and Queenstown, England 1027382
13 M237 514 1603 1887 December 18 959 Adriatic Liverpool, England and Queenstown, England 1027382
14 M237 515 61 1888 January 16 295 Adriatic Liverpool, England and Queenstown, England 1027751
15 M237 515 166 1888 February 11 733 Adriatic Liverpool, England and Queenstown, England 1027751
16 M237 518 528 1888 April 28 635 Adriatic Liverpool, England and Queenstown, England 1027754
17 M237 520 677 1888 May 25 538 Adriatic Liverpool, England 1027756
18 M237 522 844 1888 June 23 129 Adriatic Liverpool, England and Queenstown, England 1027758
19 M237 523 988 1888 July 21 243 Adriatic Liverpool, England and Queenstown, England 1027759
20 M237 524 1130 1888 August 18 208 Adriatic Liverpool, England 1027760
21 M237 525 1255 1888 September 14 213 Adriatic Liverpool, England 1027761
22 M237 526 1402 1888 October 13 214 Adriatic Liverpool, England and Queenstown, England 1027762
23 M237 527 1531 1888 November 12 69 Adriatic Liverpool, England and Queenstown, England 1027763
24 M237 528 1638 1888 December 8 183 Adriatic Liverpool, England 1027764
25 M237 529 10 1889 January 5 77 Adriatic Liverpool, England and Queenstown, England 1027765
At this point very much still a mystery. A pity too that the US 1890 census was destroyed and there are no emgration records for the US...only incoming ones.
Best wishes
Jean